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The Contender
Pro (for)
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Post Voting Period
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Voting Style: Open Point System: 7 Point
Started: 11/24/2014 Category: Science
Updated: 2 years ago Status: Post Voting Period
Viewed: 4,858 times Debate No: 65752
Debate Rounds (4)
Comments (24)
Votes (6)




Resolution: Man-Made Global Warming is a Threat.

Summary: The debate is about whether or not Man-Made Global Warming is a threat to humanity. This debate is not about natural global warming. BOP is shared.

1- No semantics.
2- Words on pictures do not go against the Character Limit (do not test it, however.)*
3- Public Opinion is unimportant. Only facts and data will be used.

*Words can be freely used in pictures to better explain the parts of the picture. Characters should be reserved for arguing data, not explaining what Line A in Chart B is supposed to be. It's up to the voters to decide if a team has gone too far and is not protected by this rule.


Team Mikal:
- Mikal
- Bluesteel
- 16kadam

Team Global:
- Donald.Keller
- Lannan13
- Subutai

Round 1: Acceptance.
Round 2: Arguments.
Round 3: Arguments and Rebuttals.
Round 4: Rebuttals and Closing Statements.

**No new contentions on Round 4.**


== Framework ==

For something to be a threat, there only needs to be a reasonable probability that it can cause harm in the future. In contrast, to show that a threat to the environment does not exist, our opponent’s must prove beyond a reasonable doubt that there is no possibility that human-caused climate change can cause harm in the future. Our opponent’s burden comes, in part, from the precautionary principle, which holds that we should not take any actions that fundamentally alter our ecosystem (such as emitting large amounts of CO2) unless we are absolutely certain that there will not be problematic consequences to doing so in the long-term. The justification for the precautionary principle is that environmental harm is irreversible and the long-term effects are hard to predict, so we should be extremely certain that our actions will not cause harm before fundamentally altering our ecosystem.

== Case ==

Contention 1: Human-caused global warming exists

The International Panel on Climate Change (IPCC) is an international group of some of the world’s most respected scientists. The IPCC has published five different reports on climate change. With each subsequent generation of report, the reports get more accurate because more datasets become available.

First, warming is happening now. According to the IPCC’s fifth report on climate change: "Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and oceans have warmed, the amounts of snow and ice have diminished, sea level has risen, and the concentrations of greenhouse gases have increased." [IPCC 5,] "It is virtually certain that globally the troposphere has warmed since the mid-20th century." [IPCC 5] The IPCC defines "virtually certain" as having a 99-100% confidence level. [IPCC 5] The IPCC also says it is virtually certain that we will have more hots days and fewer cold days over major land areas in the future. [IPCC 5] The IPCC says that it is virtually certain that increased cyclone activity is caused by global warming. [IPCC 5] "It is virtually certain that the upper ocean (0-700 m) warmed from 1971 to 2010." [IPCC 5] The IPCC says that it is virtually certain that permafrost levels will continue to decline due to global warming. [IPCC 5] "It is virtually certain that global mean sea level rise will continue beyond 2100" due to global warming. [IPCC 5] The IPCC report also contains numerous findings that are "very likely" (90-100% confidence level), but for the sake of saving space, we won't excerpt them here.

Second, recent warming is caused by human activity. "The evidence for human influence has grown since [the previous IPCC report]. It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century." [IPCC 5] "Extremely likely" is a 95-100% confidence interval. [IPCC 5] Today’s atmospheric CO2 levels are 40 percent higher than the highest natural level of CO2 that has ever existed in the last 800,000 years. [EDF,] We know that most of the increase in CO2 levels is due to burning coal and gasoline because the composition of the CO2 has a unique fingerprint that allows scientists to determine its source. [EDF] Another human activity that has increased CO2 levels is the massive clear cutting of the rainforests, which formerly acted as a huge carbon sink, absorbing large amounts of CO2. [EDF] Deforestation adds 1,500,000,000,000,000 grams of carbon to the atmosphere each year. [GCP,] Thus, humans contribute greatly to global warming.

The data proving that human-caused global warming exists has become so overwhelming that it has converted former climate skeptics, such as University of California, Berkeley, professor Richard Muller. Muller writes: “"Call me a converted skeptic. Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I’m now going a step further: Humans are almost entirely the cause. [New data from UC Berkeley] show[s] that the average temperature of the earth’s land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases. [The UC Berkeley data set is] stronger than those of [previous IPCC reports]." [NYT,]

Third, there is significant evidence in the paleoclimatic record that greenhouse gasses have a significant effect on the global temperature. Over the Cenozoic Era, which began about 66 million years ago, we can see a clear greenhouse induced warming effect within the various warming and cooling cycles. It remains very clear that CO2 remains the main driver of climate in this period. The large climate changes over the period cannot result from shifts in the climate system, but depend on both energy coming into the planet (e.g. solar rays) and changes in the atmosphere (greenhouse gasses). The sun, however, cannot be considered the dominant force of climate change in this time period because the luminosity increased by about 0.4% over this period. That alone cannot explain the warming during the Cenozoic because the Cenozoic has also seen a period of decreasing temperatures, which could only be explained by fluctuating CO2 levels (from 1000 ppm at the beginning of the Cenozoic to a low of 170 ppm). If the sun was responsible for the warming during this period, we’d see only a constant increase in temperatures. Continental movement also is unlikely as an explanation for the observed climate change during this period due to the fact that “most continents were near their present latitudes at the beginning of the Cenozoic.” Studies have concluded that “CO2 was the dominant climate forcing in the Cenozoic” [Hansen & Sato,]

Contention 2: Future harm from global warming

By 2100, global warming is estimated to cause $1.9 trillion per year in economic damages to the United States. [NRDC,] The damage includes $360 billion from destroyed real estate due to rising sea levels, $141 billion in higher energy costs due to higher demand for air conditioning, $950 billion due to the cost of providing water to places where it dries up, and $422 billion in damages from the increase in tropical storms due to global warming. [NRDC]

Future sea level rise, even by conservative estimates, are significant and would threaten “some coastal cities and low-lying island nations.” The low estimates--assuming less than 2 degrees celsius warming and a decreased temperature trend after 1950--find that there will be about half a meter sea level rise by the year 2100. [Horton et al.,]

Food production, important to the well being of society, also represents a large industry: about $200 billion a year to the US economy. Agriculture is dependent upon certain climatic conditions and altering these could prove to be catastrophic. While an initial increase in temperature may help some crops, once temperatures pass the crop’s optimal levels for growth and reproduction, increased warming becomes counterproductive. [EPA,] Some crops, like grains, grow faster when the climate is warmer, but because these crops grow faster, they have less time to fully mature, so they produce fewer edible byproducts. [EPA] Further, weeds thrive in warmer climates with more CO2 enrichments. Farmers already spend $11 billion a year combating weeds. Future temperature increases would add another burden to the industry [EPA]. Lastly, climate change dries out and acidifies soil, further impacting food production. [IPCC 4,]

Many theoretical models exist claiming that certain diseases would become more common as the climate changes. For example, increased temperatures will allow the virus that causes dengue fever to survive in more places. In 1990, 30% of the world’s population lived in regions where the estimated risk of dengue fever transmission was 50%. By 2085, 5-6 billion people (about half of the future estimated population) would live in areas where they were at risk of dengue transmission. If climate changes do not occur, only 35% of the population would be at risk. [Hales et al.,]


As you can see from our prior contentions, man made global warming is in fact a threat and can cause a great deal of harm. Even if Con casts some doubt on the harm caused by global warming, as long as we win that some harm is probable, we win this debate. Almost any amount of harm is enough for you as the judge to affirm the resolution that global warming is a threat. For the Con team to win this debate they must negate all of our contentions and statistics along with building a case of their own showing that there is in fact no threat from global warming. We can clearly see from the prior contentions that there is indeed a threat and it can and will cause harm.
Debate Round No. 1


Thank you Mikal, Bluesteel, and 16kadam. I want to establish, first, that this isn't a debate about Global Warming, but about Man-Made Global Warming. To prove his case, Pro must establish that Man-Made Global Warming is the threat. If he establishes that Global Warming is a threat, but can not establish that enough of it is man-made to say the threat comes from man, he can not affirm the resolution.

Contention 1: Human caused Global Warming Exists.

Many Global Warming advocates state that CO2 levels are skyrocketing, but that is incorrect. I give you the above graph measuring the past 600 million years of CO2 levels, which shows we are actually at an all time low. Now the website I got this from no longer has this page up so I apologize. We can see from observance of this graph that, with us being at an all time CO2 lows, that we are nowhere close to meeting the impact that my opponent brings up. The world has had CO2 levels over 5,000 ppm, while are now currently around apprx. 350 ppm CO2 levels.

The above graph shows that comparisons of C13 (Carbon isotope) and this shows that there is little to no trend in many of these as the average is zero while the trend for all of these are zero (1). This is important as the Carbon isotope is important in measuring this so called "Global Warming."

This chart above shows the CO2 and Earth's temperatures for the past 600 million years. My opponent's claims are incorrect as we have had absurd levels of CO2 and let the Global Temperature never reached the extreme levels needed to prove causation on the level Pro must prove (2).

Now I will move on to how Earth is actually cooling and how it's temperature is cooler than it has been.

If we observe the above graph we can see that Earth has been a whole lot hotter than where we currently are to the point where the Earth's average temperature is been 7.5 °C hotter than it currently it is. You can also see that in the span of the past 10,000 years the temperature has leveled off, but you may ask yourself where does that place us in the lights of modern day?

I am going to cite Dr. Done Easterbrook, who is a climate scientist. Back in 2000 he predicted that Earth was entering a cooling phase. He predicts that for the next 20 years Earth will cool by 3/10 degree each year and that we are going to enter another little Ice Age like we did from 1650 and 1790 (3). While the IPCC, the people Pro quoted, has been wrong since just before the 2000’s, while the Earth has cooled, as Dr. Done predicted.



Contention 2: Future Harm and sea levels.

Many Warming Scientists claim that the sea level rise is due to the Arctic melting, but this is false. Al Gore stated that the Arctic Ice would be completely melted by 2014, but he is incorrect then and now.

Jan. 6, 2012: The Coast Guard Cutter Healy breaks ice around the Russian-flagged tanker Renda 250 miles south of Nome. The Healy is the Coast Guard’s only currently operating polar icebreaker. The vessels are transiting through ice up to five-feet thick in this area. The 370-foot tanker Renda will have to go through more than 300 miles of sea ice to get to Nome, a city of about 3,500 people on the western Alaska coastline that did not get its last pre-winter fuel delivery because of a massive storm (4).

Let's go back to 2007-2008 and see if his claim was justified in the Arctic Ice activity.

It seems that he is incorrect, but let's look further into the near past. How about 2012-2013? (5) We all remember the Climate Scientists that got stuck in Arctic Ice Earlier this year correct? Then a Russian Ice Breaker tried to free them, but got stuck. Can you guess what they were studying? They had predicted that all the Arctic Ice had melted due to Global Warming and that Earth would get flooded massively. Boy were they wrong (6).


Dr. Koonin, former head of the Department of Energy under President Obama, has stated that Global Warming is not certain. This is because he has found 3 things wrong and highly incorrect about the theory.

1. Shrinking of Arctic Sea ice doesn't account for the gaining of the Antarctic ice.

2. Earth's temperature today is the same as it was 30 years ago.

3. The sea levels rose at the same height and rate in the 20th century. (8)

Here is another correlation that must happen. If the Ice Caps are completely melted as Pro claims then the sea level would have risen completely drowning tons of land.

The graph above is raw satellite image data of the sea level rise over an 8 year period showing that there is little to no change in the Sea Levels rising (9). The sea level rises, on average, about 3 inches per century and it has been found to not even been rising at all.

This graph is the sea levels off the cost of French Guyana which is one of the areas which is predicted to be flooded due to Global Warming, but as you can see by the graph (which goes to 2008) the sea level is currently on a downward trend (10). The source is the PDF within the link.


Contention 3 - The Benefits of a Warm Climate

A moderately warm period is better than a cold period. If the temperature is not too warm, a warm climate can have positive effects on both the Earth as a whole and on everyone.

A. Health Effects

In moderation, warm temperatures are better for the body than cold temperatures. People cannot get enough heat, infections are rampant, and hospital admissions will rise in the cold. From 1979 to 1997, extreme cold killed roughly twice as many Americans as heat waves [coincidentally when the Earth was heating up]. In Germany, heat waves were found to reduce overall mortality rates slightly, while cold spells led to a significant increase in deaths. In addition, warmer weather decreases incidences of strokes, respiratory diseases, and the flu.[1]

In general, life expectancies are higher in warmer climates, and there are fewer incidences of disease and other health problems. A warm period would be beneficial to human health.

B. Economic Benefits

Some of the major industrial sectors, particularly agriculture, tend to work better in a warmer environment than they do in a cooler environment. "The book [The Impact of Climate Change] finds that a moderate warming will have a positive economic impact on the agriculture and forestry sectors. Since carbon dioxide is used by plants to capture and store energy, there may be a fertilizing effect as levels of the gas rise. This, combined with longer growing seasons, fewer frosts and more precipitation, among other factors, could benefit some economic sectors."[2]

CO2 increases, a byproduct of temperature increases ([1]), naturally help to stimulate plant growth as well, further helping agriculture. "For a 300 ppm increase in the atmosphere's CO2 concentration above the planet's current base level of slightly less than 400 ppm, for example, the productivity of earth's herbaceous plants rises by something on the order of 30%, while the productivity of its woody plants rises by something on the order of 50%."[3][4]

This further helps humans by increasing food yields, lowering rates of starvation and hunger.

1) Singer, S. Fred, and Dennis T. Avery: "Unstoppable Global Warming: Every 1,500 Years."


Contention 3 - The Effects of CO2

Even if Pro were to establish that Global Warming is a threat, he must establish that humans cause a substantial deal of Global Warming before they can establish that Man-made Global Warming is a threat. The main case that Global Warming activists have to prove Man-Made Global Warming is a large part of the picture is the CO2 argument. it doesn’t, however, stand to fact.

Carbon Dioxide is, in fact, very weak. Having only a Global Warming Potential of 1. Carbon Dioxide makes up a grand total of 3.618% of the total Gas House Effect, with water vapor making up 95% (1). Carbon Dioxide's number increased from 295 ppm to 400 ppm, an increase of 105 ppm, equal to 49.29 gigatons (1 Gigaton of CO2 is worth 2.13 ppm (2)). Since 1 gigaton of CO2 is worth 0.004% of total Greenhouse Effect, 49.29 gigatons is worth an additional 0.21% (2). We can see the weakness of CO2 in the chart below.

If human's did raise CO2 levels by 105 ppm, the effect on the climate would be pathetic. People gravely exaggerate the effect of CO2 on the climate. The chart of Global Warming gases is as follows:


Water Vapor ------ 95.000% -- 0.001%

Carbon Dioxide -- 3.618% ---- 0.117%

Methane ------------ 0.360 ------ 0.066%

Nitrous oxide ----- 0.950% ---- 0.047%

Misc ------------------- 0.072% ---- 0.047%

Total ------------------ 100% ------- 0.278%

Following the graph, we can assume correctly that human’s CO2 emissions add very little, if almost anything at all, to Global Warming. If the man-made portion of Global Warming (0.21% of the total) was a threat, than we’d been dead from the natural Global Warming (99.79% of total) long ago. At 0.21%, the rise in temperature from our contribution would be so small that the difference in temperature from Spring to Summer would be greater.




R1) Anthropogenic Global Warming (AGW) Exists

Right from the start we can see a lot of errors from Con’s opening arguments and graphs. The first thing we want to note is that Con’s first graph about atmospheric CO2 levels is extremely misleading. Although Con doesn’t source it, Con’s graph comes from a study by Robert Berner. There are HUGE uncertainties in Berner’s guesses as to what CO2 levels were hundreds of millions of years ago. You can see in the chart below that the range of error is huge .


Also Berner himself said that the “exact values of CO2 [in his report] should not be taken literally.” [SkS1,] Berner’s guess-work therefore cannot be cited as the actual values for CO2 levels in the past.

Second, the sun was so much dimmer hundreds of millions of years ago that higher CO2 levels were needed just to prevent the Earth from freezing over. (During this period, the sun “would have been several percent dimmer according to established nuclear models of main sequence stars . . . with a dimmer sun, high CO2 is necessary to stop the Earth freezing over.”) [SkS1] Berner even said, compensating for all the factors that were different in the past, “over the long term there is indeed a correlation between CO2 and paleotemperature” [Berner and Zavareth 2001,].

Third, you can see that over the past 10,000 years, CO2 levels today are at an all time high. CO2 has risen exponentially since the start of the industrial revolution.


Unlike over a time scale of millions of years, the luminosity of the sun has been relatively constant over the last 10,000 years, so the only factor that has changed has been CO2 levels. Therefore, the only factor that can explain the temperature increase over the last 10,000 years is CO2.

Fourth, Con is blatantly wrong. The greenhouse effect is obviously a real effect that is acknowledged by every scientist in the world. When you walk into a hot car or an actual greenhouse, it has heated up so quickly because of the CO2 in the car or greenhouse. It is impossible to assert that CO2 levels have *no* effect on temperature.

The following chart shows the correlation between CO2 and temperature over the last 500 million years. The dotted line is CO2 and temperature is the solid line. The study also concludes that if you look at the luminosity of the sun alone, without accounting for CO2 levels, luminosity alone *fails* to explain temperature fluctuations.


Our opponents next cite Don Easterbrook, who predicts a cooling in the near future. However, his predictions have been outrageously incorrect for the first 10 years of its data. [SkS3,]. The following graph depicts Easterbrook’s failed predictions:


You can see from the graph that temperatures have actually increased, not declined as Eastberbook predicted.

Further, although Easterbrook portrays the IPCC’s prediction of the temperatures since 2000 as incorrect, the IPCC actually got the story much closer to reality than Easterbrook. When confronted as to where Easterbrook obtained the IPCC data, he claimed he got it from the website, but that they had deleted it. The data he portrays shows future temperature predictions based on greenhouse gasses alone, which is not the actual IPCC data from the IPCC reports (which included natural factors as well). In other words, Easterbrook’s model has failed to predict what has occurred and his refutations of IPCC findings refutes a dataset that the IPCC never even used in their report because it is not a complete picture of the causes of warming.


R2) Sea levels and ice levels

Con says that Al Gore said all the ice would be gone by now. We never cited Al Gore and there are a lot of unscientific things said in his documentary. Who cares what he said, Al Gore is not a scientist nor a viable source. Con drops the IPCC study that says ice levels will continue to decline in the future.

Con also says that some Coast Guard boat is also seeing ice up north. We have never said there is zero ice anymore. Con is just straw-manning.

Third, Con cites some sketchy tabloid-esque picture of the northern ice sheet. Taking 2 photos a year apart does not prove anything. You need to look at averages. If you take a photo on a bad day in 2012 and a really good day for the ice sheet in 2013, it might look like the ice sheet is increasing, but you have to look at annual average size, not the size on a particular date. It’s the same problem with saying “it’s cold outside today, so there’s no global warming.” If you measure global temperature on one day in 2012 and on one day in 2013 and say, “see the temperature has gone down,” that’s not proof that global temperatures are falling. Again, we need to look at yearly averages, not snapshots of a single day.

Here is the *average* amount of ice in the ice sheet over time; it’s declining (because it’s melting).

Next, Con cites Dr. Koonin, who didn’t say global warming doesn’t exist, but merely that climate models are uncertain. Something can still be a threat, even if the models are not accurate to 100% certainty.

Con also notes that temperatures have not risen dramatically over the last 30 years. This is due to a series of El Nino events that have pushed some hot water from the surface into the deep ocean. [NOAA,] This effect will not continue forever; we just got lucky that ocean circulation shifts managed to shift some heat into the deep oceans. IPCC climate models that predict an increase in temperature of 2 degrees in the future account for these El Nino events.

Con also says that sea levels have not been rising any faster than in the past. However, sea levels have been rising *twice* as fast over the last 20 years than they did in the preceding 80 years. [Nat Geo,] Con looks at an 8 year period and says the rate isn’t increasing, but the only reason that would be relevant is if the rate of CO2 emissions was a lot higher at the end of the 8 year period than at the beginning. If the amount of CO2 emitted by humans per year stayed relatively constant over this period, you wouldn’t expect sea levels to start rising any faster. Also, Con is merely cherry picking an 8 year period that looks favorable to them. If you look at trends over a broader time scale (100 years), the rate of increase has gone up.

Con then merely straw mans our argument and says that if polar ice caps had *completely* melted already (something we never claimed), then French Guyana would be underwater. We never made this claim. We only said that some island nations, like Kiribati, have thus far been swallowed by the sea. []

R3) Global warming is, on balance, good

First, Con can’t outweigh a threat. Nukes are a threat. On balance, mutually assured destruction may be beneficial to global peace, but nukes are still a “threat” to the United States. Even if something has some good effects, it can still be a threat.

Second, Con’s points don’t outweigh the harms of global warming.

(A) Health Effects

Con claims that overall health would be positively impacted by higher temperatures. However, they don’t link their source (they cite a book, but don’t provide a link or a page number). There’s no scientific explanation for why strokes or respiratory disease would decline with warmer temperatures. Research has also shown that the severity of the flu virus would *increase* (not decrease) as temperatures warmed. Warmer winters lead to more severe flu outbreaks--which, by definition, means a warming climate would make flu epidemics more widespread and harmful [ASU,].

Con also claims that “extreme cold” has killed more people than heat waves. However, “extreme cold” refers to people who have died in blizzards or while backpacking. If you don’t prepare for the cold when you go outside, you’re going to die. In contrast, people don’t die in their houses because it’s too cold; they can always throw on more blankets. People without air conditioning, however, do die from heat waves. A 2003 heatwave in Europe killed 35,000 people (mostly elderly). []

On balance, “increases in heat-related deaths due to climate change would outweigh decreases in deaths from cold-snaps.” [EPA,].

(B) Economic Effects

Con never proves that the benefits to crop outweighs the $1.9 trillion per year the US will lose due to global warming. Also, we already refuted these arguments last round. Con says that a “moderate” increase in temperatures benefits crops, but there’s no proof the increase will stay moderate and once it becomes too severe, crops are severely harmed. In addition, while crops grow faster in warmer climates, they grow too fast, leaving less time to mature, so they produce fewer edible byproducts.

R4) Effects of CO2

First, Con says we have prove that human-caused warming is a “substantial” part of warming, but we don’t have to prove it’s a substantial threat, just a threat, so this is *not* something we have to prove. The degree of danger from the threat can make it *more* of a threat, but a threat is still a threat.

Second, CO2 has a cascade effect. When CO2 causes temperature to increase a little bit, that causes more evaporation from the oceans which leads to more water vapor in the atmosphere. So even if water vapor has the largest effect on global warming, CO2 emissions cause more water vapor to be released into the air, which is called a positive feedback loop [SkS2,] (“The amplifying effect of water vapor has been observed in empirical studies such as Soden 2001”).

Third, Con is conceding the greenhouse effect exists in this contention, which destroys their first contention, where they are trying to deny that the greenhouse effect is even a real phenomenon.

Debate Round No. 2


I apologize to all - Lannan wrote the first two contentions in the last argument, but he can’t present refutations this round due to time conflictions. I (Subutai) will do my best to address Mikal’s concerns, but I will take liberties in presenting arguments that will deviate from what Lannan wrote. I also only have about an hour left, so I also apologize if anything looks sloppy.

Contention 1 - Anthropogenic Global Warming

There seems to be some disagreement between the different people writing the different arguments. I am simply going to show three reasons why an anthropogenic cause is unlikely.

First, according to the greenhouse effect, global warming should be starting from the lower atmosphere and moved to the surface (because the CO2 collects in the upper troposphere first). However, this is not happening. "...satellite and high-altitude balloon data confirm that the lower atmosphere is not trapping lots of additional heat due to higher CO2 concentrations. It is hard to know how fast the Earth's highly variable surface is warming, but it is warming faster than the lower atmosphere where the CO2 is accumulating. This is strong evidence that CO2 is not the primary climate factor."[1]

Here is a graph showing how the surface has warmed more than the troposphere:

Second, current levels of CO2 have very little effect on temperature. The greenhouse effect certainly exists, but it doesn't become linearly stronger with increasing amounts of CO2. CO2's effect on temperature is logarithmic, meaning that each additional increase has a smaller effect on the climate than the last. "The carbon that is already up in the atmosphere absorbs most of the light it can. CO2 only soaks up its favorite wavelengths of light and it's close to its saturation point. It manages to grab a bit more light from wavelengths that are close to its favorite bands but it can't do much more, because there are not many left-over photons at the right wavelengths."[2][3]

This chart shows approximately the effect that each additional increment of CO2 increase has on temperature:

Note how the pre-industrial to modern level increase has had less than a 0.2 C increase in temperature.

Third and most importantly, the predicted "hot-spot" 10 miles above the tropics that would be a signature of CO2-induced global warming is absent. "The computer models show that greenhouse warming will cause a hot-spot at an altitude between 8 and 12 km over the tropics between 30 N and 30 S. The temperature at this hot-spot is projected to increase at a rate of two to three times faster than at the surface. However, the Hadley Centre's real-world plot of radiosonde temperature observations shown below does not show the projected CO2 induced global warming hot-spot at all. The predicted hot-spot is entirely absent from the observational record. This shows that atmosphere warming theory programmed into climate models are wrong."[2]

Here is the plot of predicted temperature changes due to CO2:

However, here is the actual observed temperature changes:

The hot spot is completely missing, which is pretty much a knockout blow to the anthropogenic global warming theory.

And to be fair to Easterbrook, the IPCC isn’t very good at predicting the climate either:

The climate seems to have a mind of its own that we haven’t deciphered yet. However, it looks very unlikely that anthropogenic causes are behind the recent global warming.

[1]: Singer, S. Fred, and Dennis T. Avery: Unstoppable Global Warming: Every 1,500 Years



Contention 2 - Sea Level Rise

Even though some groups like to show scenes of global apocalypse with this, the truth is that the sea level hasn’t risen that much. However, both past and predicted rise have been greatly exaggerated. The linear trend shows a sea level rise of only 1.31 +/- 0.30 mm/year. "The Proudman Oceanographic Laboratory estimates the rate of sea level rise at 1.42 plus or minus 0.14 mm/year for the period 1954 to 2003. This is less than the estimate of 1.91 plus or minus 0.14 mm/year for the period 1902 to 1953, indicating a slowing of the rate." That’s an increase of around 2.8 inches in the last 50 years – not that much of an apocalyptic scenario.[1][2]

Future sea level predictions are even better. As of currently, global ocean heat content has not changed in recent years. Sea level itself has actually been declining for the last decade.

The ‘INQUA Commission on Sea-Level Change and Coastal Evolution’ led by Dr. Morner, prepared as estimate that the global sea level will rise 10 cm plus or minus 10 cm in the next 100 years. Dr. Morner has since revised his estimate to 5 cm per 100 years after considering data of the Sun activity suggesting that the warming trend may have ended and the Earth may be headed into a cooling trend.” That’s around 2.5 inches in the next 100 years. That’s really not too bad.[2][3]

As for Tuvalu, sea level has actually dropped four inches in the last 20 years and there is no evidence based on the observations that sea level rise there is accelerating.[4]

In general, there is no cause for concern here.





Contention 3 - Benefits of Global Warming

If we take the rest of our argument (take, for example, global warming), we see that the potential threats of global warming are only exaggerated, if not unimportant. This contention is built upon the previous arguments.

A - Health Benefits

If the flu is correlated to heat, then why is the flu worse during the winter months? In fact, the virus dies quicker in warmer weather than colder weather. The Plague of Justinian was partially caused by a colder climate.[1]

As for deaths from heat and cold, "The only global study suggests that this is true internationally: by 2050, there will be almost 400,000 more heat-related deaths a year, and almost 1.8 million fewer cold-related deaths. Warmer temperatures will save 1.4 million lives each year. The number of saved lives will outweigh the increase in heat-related deaths until at least 2200."[2]

Yes, while it is easier to make fire than an air conditioner, heat is, overall, better for the body than cold (to a point). People in the Middle East are healthier (when controlled, that is) than people in, say, Siberia. What my opponent cites is not an increase in deaths from warming per se, but in temperature variability: "The claim that warming increases morbidity rates is a myth. This isn't the case, according to Dr. Robert Mendelsohn, an environmental economist from Yale University. Mendelsohn argues that heat-stress deaths are caused by temperature variability and not warming. Those deaths grow in number not as climates warm but as the variability in climate increases."[3]

B - Economic Benefits

There’s no reason, beyond the most apocalyptic of models that the warming would be so bad that plants would be severely affected beyond what they can handle. Plus, you never responded to my claim that CO2 helps crops.




Contention IV: The Effects of CO2.

Pro is playing with words here. The idea of a threat isn’t that it’s kinda not okay, but that it is in fact an issue. A paper cut isn’t a threat, but a knife cut to the artery is. Pro must establish that Man-Made Global Warming is an actual issue that could harm0 us, not that it’s just not good. As for the term Man-Made Global Warming, it refers to the topic as it is or is likely to become. Not what it would be in an unlikely scenario. If human’s contribution to Global Warming, as it is or might be, isn’t large enough to justify being called a threat, than Pro has not affirmed the Resolution.

Regarding CO2 causing temperatures to rise enough to cause enough evaporation… This is an extreme case of slippery slope. It gravely assumes CO2 will cause that kind of increase in Water Vapor. Water Vapor is very weak. The increase in tempature needed to give Water Vapor the quantity to affirm the resolution is nearly unreachable.

I’ve already established how weak CO2 is. It would take unimaginable amounts of it to cause such an increase in Global Warming. Pro’s argument is so often quoted, but it’s simply improbable. Unless Pro can establish that Man-Made CO2 has enough of an effect to start that cycle, he can’t prove such a slippery slope.

Another flaw in Pro’s argument is that it’s ignorant of historic records. Let’s look at history... CO2 ppm is at 400 right now, but in the Mesozoic period and Cambrian Perios, it reached 2000-4000 and 7000 ppm.(5) At 7000 ppm, the temperatures were only 10ºc higher than today. Proportionately, temperatures should have been 54.23ºc higher than now. This empathizes how little of an impact CO2 has on the global temperature.

With how weak CO2 is, it would take insane quantities to accomplish what Pro claims it will. But even at 7000 ppm, it was unable to increase the temperature enough to support Pro’s case, especially if water evaporation was enough to escalate it. More evidence of the weakness of CO2 can be found in the current Global Warming Cycle. Pro shows a CO2 chart of the past 10,000 years... Here is a chart of the CO2 levels and Global Warming level from the past 400,000 years.

As we can see, despite the abnormal CO2 presence, temperatures today are actually the lowest in the past 400k years of Global Warming cycles, which are common and completely natural. Despite Pro’s claim, CO2 simply does not have the necessary effects. It may follow warmer temperatures, but warming temperatures do not follow it. When temperatures rise, CO2 rises, but when we see CO2 rise, temperatures don’t rise with it.

Historically, and even now, CO2 does not bring forth the effects needed to prove it has a substantial effect on warming. Or that it’s effect is large enough to cause temperatures to rise enough to increase Water Vapor.




We are not going to make new arguments, and keep it to a summary.

We've proven that global warming will cause massive amounts of economic harms, and a large increase in the death toll. The magnitude of the impacts are so large, even if we only prove a small probability of human-caused warming, we win that it is a "threat." The same is true of nuclear war: it is a threat because the magnitude of its impacts is so large, even if the probability of it happening is small.


Our opponents argue that tropospheric warming is minimal and that no hotspot exists. This is incorrect.

Our opponent’s first graph shows no error bars. With no source along with the graph, it is impossible to properly fact check it--we don’t know if the author of the graph is legitimate--however, we provide references with all the graphics we use, most of which coming from peer-reviewed articles. The study which proposes a lot of the anti-tropospheric warming argumentation (Douglass et al) has multiple problems with it. When errors are corrected and error bars added, models correctly replicate tropospheric warming. [RC,]

Further, research by climate skeptic John Christy eviscerates the supposed discrepancy between surface temperatures and tropospheric temperatures which the CON team brings up. When measurement error in radiosonde and satellite data are corrected, the discrepancy is erased. Only small discrepancies exist near the tropics in radiosonde data, however most researchers think the difference is due to still unknown “instrument errors” [SkS,].

Two hotspot graphs used by CON are based upon radiosonde data. These graphs attempt to show the tropospheric hot spot does not exist. However there is no discrepancy between predictions and observable measurements except in the tropics--these graphs use these locations. However, the stations in the tropics are spread out and too few in number to provide a realistic picture as to what is going on with the climate. Overall, these results should be taken with a grain of salt. When these issues are accounted for, tropospheric hotspots are found to exist [RC,].


As can be seen, there are very few radiosonde positions in the tropics.

Our opponents claim CO2 is logarithmic to temperature. We agree with this and are well versed with this piece of information. Our opponent’s graph demonstrates the effect of CO2 (with no feedbacks) is about 1 degree C of warming per doubling of CO2 (from pre industrial levels). This is accepted by both sides of the aisle. If feedbacks are included, the effect of CO2 doubling is likely 3 degrees C. The logarithmic effect also means that every doubling of CO2 will have about the same forcing (eg, 100 to 200 ppm 3 degrees, 200 to 400 another 3, etc). Again, the logarithmic effect is accepted by everyone in the field of science--the question is again, the effect of feedbacks, something our opponents have not mentioned.

CON also argues the IPCC has failed to predict temperatures. However, this is incorrect. Using an average of GISS, NASA, NOAA, NCDC, and the HADCRUT4 surface temperatures, the IPCC has accurately predicted temperatures over the period of 1990 - 2012. The IPCC predicted 0.2 degrees C warming per decade, which is well within the margin of error for actual temperatures (0.15 degrees C per decade, +/- 0.08) [SkS,].



Our opponents paint a very optimistic picture in relation to sea level rise. An extensive study in 2008, using measurements from satellites, has found that the rate of sea level rise has actually increased from 1870 - 2006. The reason for a small reduction in sea levels--which our opponents cite--are likely from the volcanic eruptions from the 1960s - 90s, which caused cooling. However, when these eruptions ceased, sea levels again rose. In fact, “the rate of rise over the five most recent 20-year periods is 25% greater than the next largest set of values during the 1940s” [Church et al.].

Our opponent’s study used more regionalized stations to measure sea level. The graph claiming no increase in heat content is based on the NODC study Levitus et al. HOWEVER, our opponents graph ONLY resembles the graph using depths of up to 700 meters. And even then, there is a significant increase in heat content increase not reported in CON’s graph. Using global ocean heat content, the rate continues to increase and does not “flatten”. Our opponents source (likely from the skeptic blogosphere) misrepresents the actual findings of the study [NOAA,].

Tuvalu is regional, not global, and therefore is not relevant to this debate. Simply because sea level is falling in one area does not mean the global average will display the same characteristics.


(a)Health Benefits

Our opponent cites our source but misrepresents its content. The flu worsens with warming temperatures because the warmer it is, the less flu there is on a certain season. However, the following season sees a dramatic outbreak of the flu significantly worse than in previous years due to the fact that 1) fewer people catch the disease and 2) threat perception decreases. And with a perception of threat low, fewer vaccinate, and therefore there is more disease in the long term.

To argue deaths from cold snaps override deaths from heatwaves is untrue. The EPA, as previously cited, was using data from a large review of the literature published by cambridge. To counter… you cite an op-ed. Now, that does not mean you are inherently incorrect, but the literature has already refuted that hypothesis. A recent publication has found that “[w]hile global tem­per­a­ture is indeed increasing, so too is the vari­ability in tem­per­a­ture extremes”. They also found, “this means that even as overall tem­per­a­tures rise, we may still con­tinue to expe­ri­ence extreme cold snaps” [SD,]. In other words, not only will people die from heat waves, but cold snaps will still exist and will still cause substantial harm, negating the premise of Lomborg’s op-ed. The World Health Organization also disagrees, arguing the effect to human health will be catastrophic. In one large heat wave in Europe, “more than 70,000 excess deaths were recorded” [WHO,].

Our opponents have also ignored our argument on Dengue fever and other tropical illnesses. The dengue fever used to be only a tropical disease, but climate change has caused it to be much more widespread. Further, malaria and other infectious diseases are destined to kill more people as the climate warms [Wiki,].

(b) Economic effects

Our opponents claim we never responded to their position on crops. This is incorrect. We did in all of our rounds. We demonstrated a harm to the farming economy, and the fact that more CO2 = faster maturing plants, which = fewer plant yields. The NRC has looked at the literature, and finds that if the world warms 3 degrees C, crop yields will fall dramatically. If it increases, 2 degrees, there will still be a decrease. And if it increases 1 degree (this is with no feedbacks), there will be a decrease in yields except in mid latitude areas. Overall, the effect will be negative [Wiki,].

[Wiki; NRC]


To claim that water vapor is weak is contradictory to previous claims you have made, which argue water vapor is the primary greenhouse gas. Without feedbacks, the doubling of CO2 will increase temperatures by 1 degree celsius. This is not “insignificant”, and is enough to begin the positive feedback loop. Empiricals studies have demonstrated this effect, and climate sensitivity is generally considered about 3 degrees C per doubling of CO2 [Held,].

Further, our opponent’s math is incorrect. It takes about 5 co2 doublings from the pre-industrial period to reach 7000 ppm. This, with sensitivity and the logarithmic effect accounted for, would lead to 15 degrees C of warming, not 54 degrees. This is within the margin of error, meaning the examples presented do not disprove the relationship between CO2 and temperature. Further, the temperature was closer to +15 degrees, not +10 like CON argues. In the Cambrian, there is no real accurate picture of what temperatures were like, due to the fact it was so long ago. Further, these calculations fail to account for the position of the continents or the sun, which also affect climate. Where the landmass was in the cretaceous is “may have had a radiative effect equivalent to +1 CO2 doubling” [Royer, personal correspondence]. This means that to get an accurate picture of the climate, we have to account for other factors. In fact, recent research has demonstrated this, and finds that the climate sensitivity to CO2 is at least 3 degrees C [Royer 2014,]. The fact is, a look into history supports AGW theory, it does not weaken it.

Again, a graph which does not show much at all. It does not account for other factors which may be stunting warming (e.g. aerosols). The IPCC has looked into the evidence within this time frame, and finds that “it is very likely that glacial-interglacial CO2 variations have strongly amplifed climate variations” [IPCC,].

Debate Round No. 3


Global_Team.1 forfeited this round.


Extend arguments

And thanks to our opposition for trying their best
Debate Round No. 4
24 comments have been posted on this debate. Showing 1 through 10 records.
Posted by 16kadams 2 years ago
I kinda want to vote on this debate for CON just for mercy :P
Posted by 16kadams 2 years ago
Yes, water vapor. It is the most significant greenhouse gas, even the CON side agrees with this. The positive feedback loop occurs because the direct warming (about 1 degree C) from doubling CO2 leads to an increase in temperatures, which leads to more water vapor, which leads to more warming. When other feedbacks (including clouds) are taken into effect, a median measurement of climate sensitivity is about 3 degrees C. This, as we argued, was supported by the paleoclimate research which puts climate sensitivity to CO2 at 1.4 - 6 degrees C, with a best estimate of 3 degrees C, which agrees with the IPCC AR4 and 5 reports.
Posted by Romanii 2 years ago
well... there goes this debate's chances of making the hall of fame....
Posted by Vajrasattva-LeRoy 2 years ago
I'm afraid that I don't agree with your conclusions.

I've read that the evidence supporting the claim that Man-made sources of things that supposedly cause Global Warming is weak or even nonexistent,
& I tend to agree with that view.

Just as one example, you've apparently stated that Water Vapor is accepted as a major cause of Global Warming.
C'mon !
Water Vapor???
About 70% of the earth's planet is covered with water ...
Posted by 16kadams 2 years ago
Go ahead
Posted by Mikal 2 years ago
round 4?

Posted by Subutai 2 years ago
Can I at least have a critique of my arguments from round 3?
Posted by 16kadams 2 years ago
Posted by Global_Team.1 2 years ago
We lost interest in the debate as soon as round 1 started. I'm surprise it took this long for us to stop writing arguments. A lack of coordination and interest hurt our effort a lot.
Posted by 16kadams 2 years ago
if the CON teams wishes to see my personal correspondence with Dana Royer, PhD, I am willing to send them the emails (so they can verify the source).
6 votes have been placed for this debate. Showing 1 through 6 records.
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