|
Skeptic Argument |
One Liner |
Paragraph |
| 2 |
"It's the sun" |
In the last 35 years of global warming, sun and climate have been going in opposite directions |
In the last 35 years of global warming, the sun has shown a slight cooling trend. Sun and climate have been going in opposite directions. |
| 4 |
"There is no consensus" |
97% of climate experts agree humans are causing global warming. |
That humans are causing global warming is the position of the Academies of Science from 19 countries plus many scientific organizations that study climate science. More specifically, around 95% of active climate researchers actively publishing climate papers endorse the consensus position. |
| 6 |
"Models are unreliable" |
Models successfully reproduce temperatures since 1900 globally, by land, in the air and the ocean. |
While there are uncertainties with climate models, they successfully reproduce the past and have made predictions that have been subsequently confirmed by observations. |
| 8 |
"Animals and plants can adapt" |
Global warming will cause mass extinctions of species that cannot adapt on short time scales. |
A large number of ancient mass extinction events have been strongly linked to global climate change. Because current climate change is so rapid, the way species typically adapt (eg - migration) is, in most cases, simply not be possible. Global change is simply too pervasive and occurring too rapidly. |
| 10 |
"Antarctica is gaining ice" |
Satellites measure Antarctica losing land ice at an accelerating rate. |
While the interior of East Antarctica is gaining land ice, overall Antarctica is losing land ice at an accelerating rate. Antarctic sea ice is growing despite a strongly warming Southern Ocean. |
| 12 |
"CO2 lags temperature" |
CO2 didn't initiate warming from past ice ages but it did amplify the warming. |
When the Earth comes out of an ice age, the warming is not initiated by CO2 but by changes in the Earth's orbit. The warming causes the oceans to give up CO2. The CO2 amplifies the warming and mixes through the atmosphere, spreading warming throughout the planet. So CO2 causes warming AND rising temperature causes CO2 rise. |
| 14 |
"We're heading into an ice age" |
Worry about global warming impacts in the next 100 years, not an ice age in over 10,000 years. |
The warming effect from more CO2 greatly outstrips the influence from changes in the Earth's orbit or solar activity, even if solar levels were to drop to Maunder Minimum levels. |
| 16 |
"Hockey stick is broken" |
Recent studies agree that recent global temperatures are unprecedented in the last 1000 years. |
Since the hockey stick paper in 1998, there have been a number of proxy studies analysing a variety of different sources including corals, stalagmites, tree rings, boreholes and ice cores. They all confirm the original hockey stick conclusion: the 20th century is the warmest in the last 1000 years and that warming was most dramatic after 1920. |
| 18 |
"Climategate CRU emails suggest conspiracy" |
A number of investigations have cleared scientists of any wrongdoing in the media-hyped email incident. |
While some of the private correspondance is not commendable, an informed examination of their 'suggestive' emails reveal technical discussions using techniques well known in the peer reviewed literature. Focusing on a few suggestive emails merely serves to distract from the wealth of empirical evidence for man-made global warming. |
| 20 |
"Al Gore got it wrong" |
Al Gore book is quite accurate, and far more accurate than contrarian books. |
While there are minor errors in An Inconvenient Truth, the main truths presented - evidence to show mankind is causing global warming and its various impacts is consistent with peer reviewed science. |
| 22 |
"1934 - hottest year on record" |
1934 was one of the hottest years in the US, not globally. |
1934 is the hottest year on record in the USA which only comprises 2% of the globe. According to NASA temperature records, the hottest year on record globally is 2005. |
| 24 |
"Sea level rise is exaggerated" |
A variety of different measurements find steadily rising sea levels over the past century. |
Sea levels are measured by a variety of methods that show close agreement - sediment cores, tidal gauges, satellite measurements. What they find is sea level rise has been steadily accelerating over the past century. |
| 26 |
"Mars is warming" |
Mars is not warming globally. |
Martian climate is primarily driven by dust and albedo and there is little empirical evidence that Mars is showing long term warming. |
| 28 |
"Increasing CO2 has little to no effect" |
The strong CO2 effect has been observed by many different measurements. |
An enhanced greenhouse effect from CO2 has been confirmed by multiple lines of empirical evidence. Satellite measurements of infrared spectra over the past 40 years observe less energy escaping to space at the wavelengths associated with CO2. Surface measurements find more downward infrared radiation warming the planet's surface. This provides a direct, empirical causal link between CO2 and global warming. |
| 30 |
"Oceans are cooling" |
The most recent ocean measurements show consistent warming. |
Early estimates of ocean heat from the Argo showed a cooling bias due to pressure sensor issues. Recent estimates of ocean heat that take this bias into account show continued warming of the upper ocean. This is confirmed by independent estimates of ocean heat as well as more comprehensive measurements of ocean heat down to 2000 metres deep. |
| 32 |
"Human CO2 is a tiny % of CO2 emissions" |
The natural cycle adds and removes CO2 to keep a balance; humans add extra CO2 without removing any. |
The CO2 that nature emits (from the ocean and vegetation) is balanced by natural absorptions (again by the ocean and vegetation). Therefore human emissions upset the natural balance, rising CO2 to levels not seen in at least 800,000 years. In fact, human emit 26 gigatonnes of CO2 per year while CO2 in the atmosphere is rising by only 15 gigatonnes per year - much of human CO2 emissions is being absorbed by natural sinks. |
| 34 |
"IPCC is alarmist" |
The IPCC summarizes the recent research by leading scientific experts. |
The IPCC lead authors are experts in their field, instructed to fairly represent the full range of the up-to-date, peer-reviewed literature. Consequently, the IPCC reports tend to be cautious in their conclusions. Comparisons to the most recent data consistently finds that climate change is occurring more rapidly and intensely than indicated by IPCC predictions.
|
| 36 |
"Polar bear numbers are increasing" |
Polar bears are in danger of extinction as well as many other species. |
While there is some uncertainty on current polar bear population trends, one thing is certain. No sea ice means no seals which means no polar bears. With Arctic sea ice retreating at an accelerating rate, the polar bear is at grave risk of extinction |
| 38 |
"CO2 limits will harm the economy" |
The benefits of a price on carbon outweigh the costs several times over. |
Economic assessments of proposed policy to put a price on carbon emissions are in widespread agreement that the net economic impact will be minor. The costs over the next several decades center around $100 per average family, or about 75 cents per person per day, and a GDP reduction of less than 1%. |
| 40 |
"Other planets are warming" |
Mars and Jupiter are not warming, and anyway the sun has recently been cooling slightly. |
There are three fundamental flaws in the 'other planets are warming' argument. Not all planets in the solar system are warming. The sun has shown no long term trend since 1950 and in fact has shown a slight cooling trend in recent decades. There are explanations for why other planets are warming. |
| 42 |
"There's no empirical evidence" |
There are multiple lines of direct observations that humans are causing global warming. |
Direct observations find that CO2 is rising sharply due to human activity. Satellite and surface measurements find less energy is escaping to space at CO2 absorption wavelengths. Ocean and surface temperature measurements find the planet continues to accumulate heat. This gives a line of empirical evidence that human CO2 emissions are causing global warming. |
| 44 |
"We're coming out of the Little Ice Age" |
Scientists have determined that the factors which caused the Little Ice Age cooling are not currently causing global warming |
The main driver of the warming from the Little Ice Age to 1940 was the warming sun with a small contribution from volcanic activity. However, solar activity leveled off after 1940 and the net influence from sun and volcano since 1940 has been slight cooling. Greenhouse gases have been the main contributor of warming since 1970. |
| 46 |
"It cooled mid-century" |
Mid-century cooling involved aerosols and is irrelevant for recent global warming. |
There are a number of forcings which affect climate (eg - stratospheric aerosols, solar variations). When all forcings are combined, they show good correlation to global temperature throughout the 20th century including the mid-century cooling period. However, for the last 35 years, the dominant forcing has been CO2. |
| 48 |
"Satellites show no warming in the troposphere" |
The most recent satellite data show that the earth as a whole is warming. |
Satellite measurements match model results apart from in the tropics. There is uncertainty with the tropical data due to how various teams correct for satellite drift. The U.S. Climate Change Science Program concludes the discrepancy is most likely due to data errors. |
| 50 |
"It's aerosols" |
Aerosols have been masking global warming, which would be worse otherwise. |
The global dimming trend reversed around 1990 - 15 years after the global warming trend began in the mid 1970's. |
| 52 |
"There's no tropospheric hot spot" |
We see a clear "short-term hot spot" - there's various evidence for a "long-term hot spot". |
Satellite measurements match model results apart from in the tropics. There is uncertainty with the tropic data due to how various teams correct for satellite drift. The U.S. Climate Change Science Program conclude the discrepancy is most likely due to data errors. |
| 54 |
"2009-2010 winter saw record cold spells" |
A cold day in Chicago in winter has nothing to do with the trend of global warming. |
The cold snap is due to a strong phase of the Arctic Oscillation. This is causing cool temperatures at mid-latitudes (eg - Eurasia and North America) and warming in polar regions (Greenland and Arctic Ocean). The warm and cool regions roughly balance each other out with little impact on global temperature. |
| 56 |
"It's not us" |
Multiple sets of independent observations find a human fingerprint on climate change. |
The human fingerprint in global warming is evident in multiple lines of empirical evidence - in satellite measurements of outgoing infrared radiation, in surface measurements of downward infrared radiation, in the cooling stratosphere and other metrics. |
| 58 |
"Scientists can't even predict weather" |
Weather and climate are different; climate predictions do not need weather detail. |
Weather is chaotic, making prediction difficult. However, climate takes a long term view, averaging weather out over time. This removes the chaotic element, enabling climate models to successfully predict future climate change. |
| 60 |
"IPCC were wrong about Himalayan glaciers" |
Glaciers are in rapid retreat worldwide, despite 1 error in 1 paragraph in a 1000 page IPCC report. |
The IPCC error on the 2035 prediction was unfortunate and it's important that such mistakes are avoided in future publications through more rigorous review. But the central message of the IPCC AR4, is confirmed by the peer reviewed literature. The Himalayan glaciers are of vital importance, providing drinking water to half a billion people. Satellites and on-site measurements are observing that Himalayan glaciers are disappearing at an accelerating rate. |
| 62 |
"Sea level rise predictions are exaggerated" |
Sea level rise is now increasing faster than predicted due to unexpectedly rapid ice melting. |
Observed sea levels are actually tracking at the upper range of the IPCC projections. When accelerating ice loss from Greenland and Antarctica are factored into sea level projections, the estimated sea level rise by 2100 is between 75cm to 2 metres. |
| 64 |
"It's the ocean" |
The oceans are warming and moreover are becoming more acidic, threatening the food chain. |
Oceans are warming across the globe. In fact, globally oceans are accumulating energy at a rate of 4 x 1021 Joules per year - equivalent to 127,000 nuclear plants (which have an average output of 1 gigawatt) pouring their energy directly into the world's oceans. This tells us the planet is in energy imbalance - more energy is coming in than radiating back out to space. |
| 66 |
"Clouds provide negative feedback" |
Evidence is building that net cloud feedback is likely positive and unlikely to be strongly negative. |
Although the cloud feedback is one of the largest remaining uncertainties in climate science, evidence is building that the net cloud feedback is likely positive, and unlikely to be strongly negative. |
| 68 |
"CO2 effect is saturated" |
Direct measurements find that rising CO2 is trapping more heat. |
If the CO2 effect was saturated, adding more CO2 should add no additional greenhouse effect. However, satellite and surface measurements observe an enhanced greenhouse effect at the wavelengths that CO2 absorb energy. This is empirical proof that the CO2 effect is not saturated. |
| 70 |
"The science isn't settled" |
That human CO2 is causing global warming is known with high certainty & confirmed by observations. |
Science is never 100% settled - science is about narrowing uncertainty. Different areas of science are understood with varying degrees of certainty. For example, we have a lower understanding of the effect of aerosols while we have a high understanding of the warming effect of carbon dioxide. Poorly understood aspects of climate change do not change the fact that a great deal of climate science is well understood. |
| 72 |
"It's methane" |
Methane plays a minor role in global warming but could get much worse if permafrost starts to melt. |
While methane is a more potent greenhouse gas than CO2, there is over 200 times more CO2 in the atmosphere. Hence the amount of warming methane contributes is 28% of the warming CO2 contributes. |
| 74 |
"Humidity is falling" |
Multiple lines of independent evidence indicate humidity is rising and provides positive feedback. |
To claim that humidity is decreasing requires you ignore a multitude of independent reanalyses that all show increasing humidity. It requires you accept a flawed reanalysis that even its own authors express caution about. It fails to explain how we can have short-term positive feedback and long-term negative feedback. In short, to insist that humidity is decreasing is to neglect the full body of evidence. |
| 76 |
"CO2 measurements are suspect" |
CO2 levels are measured by hundreds of stations across the globe, all reporting the same trend. |
CO2 levels are measured by hundreds of stations scattered across 66 countries which all report the same rising trend. |
| 78 |
"Jupiter is warming" |
Jupiter is not warming, and anyway the sun is cooling. |
Jupiter's climate change is due to shifts in internal turbulence fueled from an internal heat source - the planet radiates twice as much energy as it receives from the sun. |
| 80 |
"500 scientists refute the consensus" |
Around 97% of climate experts agree that humans are causing global warming. |
Close inspection of the studies alleged to refute man-made global warming finds that many of these papers do no such thing. Of the few studies that do claim to refute man-made global warming, these repeat well debunked myths. |
| 82 |
"CO2 is not increasing" |
CO2 is increasing rapidly, and is reaching levels not seen on the earth for millions of years. |
Currently, humans are emitting around 29 billion tonnes of carbon dioxide into the atmosphere per year. Around 43% remains in the atmosphere - this is called the 'airborne fraction'. The rest is absorbed by vegetation and the oceans. While there are questions over how much the airborne fraction is increasing, it is clear that the total amount of CO2 in the atmosphere is increasing dramatically. Current CO2 levels are the highest in 15 million years. |
| 84 |
"Solar Cycle Length proves its the sun" |
The sun has not warmed since 1970 and so cannot be driving global warming. |
The claim that solar cycle length proves the sun is driving global warming is based on a single study published in 1991.
Subsequent research, including a paper by a co-author of the original 1991 paper, finds the opposite conclusion. Solar cycle length as a proxy for solar activity tells us the sun has had very little contribution to global warming since 1975. |
| 86 |
"CO2 is coming from the ocean" |
The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result. |
Measurements of carbon isotopes and falling oxygen in the atmosphere show that rising carbon dioxide is due to the burning of fossil fuels and cannot be coming from the ocean. |
| 88 |
"IPCC overestimate temperature rise" |
Monckton used the IPCC equation in an inappropriate manner. |
Lord Monckton has taken a single equation from the IPCC, used it in an inappropriate manner, and then attributed his results to the IPCC. This is as if I borrowed your car, drove into a tree, and then blamed you. He uses a method that is clearly intended to examine the long-term response of temperature to changes in carbon dioxide, and which is never used by the IPCC (nor should it be) to make predictions about current temperature trends. A slight change in Lord Monckton’s methodology as of July 2010 still does not make his method or attribution remotely appropriate. |
| 90 |
"Peer review process was corrupted" |
An Independent Review concluded that CRU's actions were normal and didn't threaten the integrity of peer review. |
The Independent Climate Change Email Review investigated the CRU scientists' actions relating to peer review. In one case, it judged their strong reaction to a controversial paper was not unusual. In another, it turned out the alleged victim had actually been spreading malicious rumours about CRU. In a third, the allegation of collusion fell apart when the full email exchange was examined. The Review concluded that CRU's actions were normal and did not threaten the integrity of peer review. |
| 92 |
"It's albedo" |
Albedo change in the Arctic, due to receding ice, is increasing global warming. |
The long term trend from albedo is that of cooling. In recent years, satellite measurements of albedo show little to no trend. |
| 94 |
"Dropped stations introduce warming bias" |
If the dropped stations had been kept, the temperature would actually be slightly higher. |
Dropped weather stations actually show a slightly warmer trend compared to kept stations. So the removal of these faster warming dropped stations has actually imposed a slight cooling trend although the difference is negligible since 1970. |
| 96 |
"Phil Jones says no global warming since 1995" |
Phil Jones was misquoted. |
When you read Phil Jones' actual words, you see he's saying there is a warming trend but it's not statistically significant. He's not talking about whether warming is actually happening. He's discussing our ability to detect that warming trend in a noisy signal over a short period. |
| 98 |
"Lindzen and Choi find low climate sensitivity" |
Lindzen and Choi’s paper is viewed as unacceptably flawed by other climate scientists. |
Lindzen's analysis has several flaws, such as only looking at data in the tropics. A number of independent studies using near-global satellite data find positive feedback and high climate sensitivity. |
| 100 |
"It's too hard" |
Scientific studies have determined that current technology is sufficient to reduce greenhouse gas emissions enough to avoid dangerous climate change. |
The argument that solving the global warming problem by reducing human greenhouse gas emissions is "too hard" generally stems from the belief that (i) our technology is not sufficiently advanced to achieve significant emissions reductions, and/or (ii) that doing so would cripple the global economy. However, studies have determined that current technology is sufficient to reduce greenhouse gas emissions the necessary amount, and that we can do so without significant impact on the economy. |
| 102 |
"It's global brightening" |
This is a complex aerosol effect with unclear temperature significance. |
Global brightening is caused by changes in cloud cover, reflective aerosols and absorbing aerosols. While these changes lead to more sunlight hitting the surface, they also have a cooling effect due to clouds trapping less warmth and absorbing aerosols absorbing less sunlight. The net effect of global brightening is considerably smaller than the forcing from CO2. |
| 104 |
"It's a climate regime shift" |
There is no evidence that climate has chaotic “regimes” on a long-term basis. |
A full reading of Tsonis and Swanson's research shows that internal variability from climate shifts merely cause temporary slow downs or speeding up of the long-term warming trend. When the internal variability is removed from the temperature record, what we find is nearly monotonic, accelerating warming throughout the 20th Century. |
| 106 |
"Solar cycles cause global warming" |
Over recent decades, the sun has been slightly cooling & is irrelevant to recent global warming. |
A full reading of Tung 2008 finds a distinct 11 year solar signal in the global temperature record. However, this 11 year cycle is superimposed over the long term global warming trend. In fact, the authors go on to estimate climate sensitivity from their findings, calculate a value between 2.3 to 4.1°C. This confirms the IPCC estimate of climate sensitivity. |
| 108 |
"Earth hasn't warmed as much as expected" |
This argument ignores the cooling effect of aerosols and the planet's thermal inertia. |
The argument that "Earth hasn't warmed as much as expected" generally relies on ignoring the factors which have a cooling effect on the Earth's temperatures, and the planet's thermal inertia, which delays the full amount of global warming. When we do the calculations and include all radiative forcings and the amount of heat being absorbed by the oceans, it shows that the Earth has warmed almost exactly as much as we would expect. |
| 110 |
"It's ozone" |
Ozone has only a small effect. |
Multiple satellite measurements and ground-based observations have determined the ozone layer has stopped declining since 1995 while temperature trends continue upwards. |
| 112 |
"Tuvalu sea level isn't rising" |
Tuvalu sea level is rising 3 times larger than the global average. |
Between 1950-2009 sea level at Tuvalu rose at the rate of 5.1 (±0.7) mm per year. This is almost 3 times larger than average global sea level rise over the same period. |
| 114 |
"Trenberth can't account for the lack of warming" |
Trenberth is talking about the details of energy flow, not whether global warming is happening. |
Trenberth's views are clarified in the paper "An imperative for climate change planning: tracking Earth's global energy". We know the planet is continually heating due to increasing carbon dioxide but that surface temperature sometimes have short term cooling periods. This is due to internal variability and Trenberth was lamenting that our observation systems can't comprehensively track all the energy flow through the climate system. |
| 116 |
"Renewables can't provide baseload power" |
A number of renewable sources already do provide baseload power, and we don't need renewables to provide a large percentage of baseload power immediately. |
Although renewable energy does not necessarily need to provide baseload power in the short-term, there are several ways in which it can do so. For example, geothermal energy is available at all times, concentrated solar thermal energy has storage capability, and wind energy can be stored in compressed air. |
| 118 |
"Naomi Oreskes' study on consensus was flawed" |
Benny Peiser, the Oreskes critic, retracted his criticism. |
An examination of the papers that critics claim refute the consensus are found to actually endorse the consensus or are review papers (eg - they don't offer any new research but merely review other papers). This led the original critic Benny Peiser to retract his criticism of Oreskes' study. |
| 120 |
"A drop in volcanic activity caused warming" |
Volcanoes have had no warming effect in recent global warming - if anything, a cooling effect. |
A drop of volcanic activity in the early 20th century may have had a warming effect. However, volcanoes have had no warming effect in the last 40 years of global warming. If anything, they've imposed a slight cooling effect. |
| 122 |
"Satellite error inflated Great Lakes temperatures" |
Temperature errors in the Great Lakes region are not used in any global temperature records. |
Temperature errors in the Great Lakes region are not incorporated in any of the global mean temperature records. In particular, there is no connection to the satellite microwave temperature analyses by RSS and UAH, which use entirely different sensors operating in a quite different portion of the electromagnetic spectrum. |
| 124 |
"Soares finds lack of correlation between CO2 and temperature" |
Soares looks at short-term trends which are swamped by natural variations while ignoring the long-term correlation. |
Soares looks at short-term trends which are swamped by natural variations. Increasing CO2 causes a gradual long-term warming trend which is smaller than the short-term variations. The long-term correlation between CO2 and temperature is well established. |
| 126 |
"Most of the last 10,000 years were warmer" |
This argument uses regional temperature data that ends in 1855, long before modern global warming began. |
This argument uses temperatures from the top of the Greenland ice sheet. This data ends in 1855, long before modern global warming began. It also reflects regional Greenland warming, not global warming. |
| 128 |
"It's waste heat" |
Greenhouse warming is adding 100 times more heat to the climate than waste heat. |
The contribution of waste heat to the global climate is 0.028 W/m2. In contrast, the contribution from human greenhouse gases is 2.9 W/m2. Greenhouse warming is adding about 100 times more heat to our climate than waste heat. |
| 130 |
"It warmed just as fast in 1860-1880 and 1910-1940" |
The warming trend over 1970 to 2001 is greater than warming from both 1860 to 1880 and 1910 to 1940. |
Statistical analysis of the rate of warming over different periods find that warming from 1970 to 2001 is greater than the warming from both 1860 to 1880 and 1910 to 1940. |
| 132 |
"The sun is getting hotter" |
The sun has just had the deepest solar minimum in 100 years. |
Various independent measurements of solar activity all confirm the sun has shown a slight cooling trend since 1978. |
| 134 |
"An exponential increase in CO2 will result in a linear increase in temperature" |
CO2 levels are rising so fast that unless we decrease emissions, global warming will accelerate this century. |
Despite the logarithmic relationship between CO2 and surface temperatures, atmospheric CO2 levels are rising so fast that unless we dramatically decrease our emissions, global warming will accelerate over the 21st Century. |
| 136 |
"CERN CLOUD experiment proved cosmic rays are causing global warming" |
The CERN CLOUD experiment only tested one-third of one out of four requirements necessary to blame global warming on cosmic rays, and two of the other requirements have already failed. |
The CERN CLOUD experiment only tested one-third of one out of four requirements necessary to blame global warming on cosmic rays, and two of the other requirements have already failed. |
| 138 |
"Skeptics were kept out of the IPCC?" |
Official records, Editors and emails suggest CRU scientists acted in the spirit if not the letter of IPCC rules. |
The Independent Climate Change Email Review investigated the CRU scientists' actions as IPCC authors. Official records, Review Editors, and even the emails themselves suggest the CRU scientists acted in the spirit if not the letter of the IPCC rules. Anyway, the relevant texts were team responsibilities. |
| 140 |
"CO2 was higher in the late Ordovician" |
The sun was much cooler during the Ordovician. |
During the Ordovician, solar output was much lower than current levels. Consequently, CO2 levels only needed to fall below 3000 parts per million for glaciation to be possible. The latest CO2 data calculated from sediment cores show that CO2 levels fell sharply during the late Ordovician due to high rock weathering removing CO2 from the air. Thus the CO2 record during the late Ordovician is entirely consistent with the notion that CO2 is a strong driver of climate. |
| 142 |
"Scientists retracted claim that sea levels are rising" |
The Siddall 2009 paper was retracted because its predicted sea level rise was too low. |
The retracted paper actually predicts a low range of future sea level rise. The retraction removes a lower bound of sea level prediction. This increases confidence in other peer-reviewed research predicting sea level rise of 80cm to 2 metres by 2100. |
| 144 |
"Greenland has only lost a tiny fraction of its ice mass" |
Greenland's ice loss is accelerating & will add metres of sea level rise in upcoming centuries. |
Multiple lines of evidence indicate Greenland's ice loss is accelerating and will contribute sea level rise in the order of metres over the next few centuries. |
| 146 |
"DMI show cooling Arctic" |
While summer maximums have showed little trend, the annual average Arctic temperature has risen sharply in recent decades. |
While summer maximums have showed little trend, the annual average Arctic temperature has risen sharply in recent decades. |
| 148 |
"Royal Society embraces skepticism" |
The Royal Society still strongly state that human activity is the dominant cause of global warming. |
The Royal Society states that "There is strong evidence that changes in greenhouse gas concentrations due to human activity are the dominant cause of the global warming that has taken place over the last half century" and "The decade 2000-2009 was, globally, around 0.15 °C warmer than the decade 1990-1999". They are not denying anthropogenic global warming. |
| 150 |
"CO2 only causes 35% of global warming" |
CO2 and corresponding water vapor feedback are the biggest cause of global warming. |
The Nature commentary by Penner et al. on which this argument is based actually says that on top of the global warming caused by carbon dioxide, other short-lived pollutants (such as methane and black carbon) cause an additional warming approximately 65% as much as CO2, and other short-lived pollutants (such as aerosols) also cause some cooling. However, claiming that CO2 has only caused 35% of global warming is a gross misinterpretation and misunderstanding of the paper. |
| 152 |
"Postma disproved the greenhouse effect" |
Postma's model contains many simple errors; in no way does Postma undermine the existence or necessity of the greenhouse effect. |
Joseph Postma published an article criticizing a very simple model that nonetheless produces useful results. He made several very simple errors along the way, none of which are very technical in nature. In no way does Postma undermine the existence or necessity of the greenhouse effect. |