Arguments from Global Warming Skeptics and what the science really says


Skeptic Arguments and What the Science Says

Here is a summary of what the science says on each skeptic argument. You can also view the arguments sorted by taxonomy or a print-friendly version.

Skeptic Argument vs What the Science Says
1 “It’s the sun” The sun’s output has barely changed since 1970 and is irrelevant to recent global warming.
2 “Climate’s changed before” The climate reacts to whatever forces it to change at the time, which now is dominated by humans.
3 “There is no consensus” Around 95% of climate experts agree that humans are causing global warming.
4 “It’s cooling” The last decade 2000-2009 was the hottest on record.
5 “Models are unreliable” Models successfully reproduce temperatures since 1900 globally, by land, in the air and the ocean.
6 “Temp record is unreliable” The warming trend is the same in rural and urban areas, measured by thermometers and satellites.
7 “It hasn’t warmed since 1998” 2005 was the hottest year globally, and 2009 the second hottest.
8 “Ice age predicted in the 70s” The vast majority of climate papers in the 1970s predicted warming.
9 “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.
10 “Antarctica is gaining ice” Satellites measure Antarctica losing land ice at an accelerating rate.
11 “CO2 lags temperature” Recent CO2 increase has caused recent warming without any time lag.
12 “It’s not bad” Negative impacts of global warming on agriculture, health & environment far outweigh any positives.
13 “Al Gore got it wrong” Al Gore’s book is quite accurate, and far more accurate than contrarian books.
14 “It’s cosmic rays” Cosmic rays show no trend over the last 30 years & have had little impact on recent global warming.
15 “It’s freaking cold!” A local cold day has nothing to do with the long-term trend of increasing global temperatures.
16 “Hurricanes aren’t linked to global warming” There is increasing evidence that hurricanes are getting stronger due to global warming.
17 “1934 – hottest year on record” 1934 was not the hottest year globally, only in the US.
18 “Hockey stick is broken” Recent studies agree that recent global temperatures are unprecedented in the last 1000 years.
19 “Mars is warming” Mars is not warming globally.
20 “It’s Urban Heat Island effect” Urban and rural regions show the same warming trend.
21 “It’s just a natural cycle” Ancient natural cycles are irrelevant for attributing recent global warming to humans.
22 “Arctic icemelt is a natural cycle” Thick arctic sea ice is undergoing a rapid retreat.
23 “Sea level rise is exaggerated” A variety of different measurements find steadily rising sea levels over the past century.
24 “Water vapor is the most powerful greenhouse gas” Rising CO2 increases atmospheric water vapor, which makes global warming much worse.
25 “Other planets are warming” Mars and Jupiter are not warming, and anyway the sun has recently been cooling slightly.
26 “Greenland was green” Other parts of the earth got colder when Greenland got warmer.
27 “Oceans are cooling” The most recent ocean measurements show consistent warming.
28 “Climategate CRU emails suggest conspiracy” Several investigations have cleared scientists of any wrongdoing in the media-hyped email incident.
29 “Human CO2 is a tiny % of CO2 emissions” Human-caused CO2 emissions upset the natural balance and are causing global warming.
30 “Climate sensitivity is low” Net positive feedback is confirmed by many different lines of evidence.
31 “CO2 effect is weak” The strong CO2 effect has been observed by many different measurements.
32 “We’re coming out of the Little Ice Age” The sun was warming up then, but the sun hasn’t been warming since 1970.
33 “It cooled mid-century” Mid-century cooling involved aerosols and is irrelevant for recent global warming.
34 “Glaciers are growing” Most glaciers are retreating, posing a serious problem for millions who rely on glaciers for water.
35 “It warmed before 1940 when CO2 was low” Early 20th century warming is due to several causes, including rising CO2.
36 “There’s no empirical evidence” There are multiple lines of direct observations that humans are causing global warming.
37 “Polar bear numbers are increasing” Polar bears are in danger of extinction as well as many other species.
38 “Satellites show no warming in the troposphere” The most recent satellite data show that the earth as a whole is warming.
39 “Mt. Kilimanjaro’s ice loss is due to land use” Most glaciers are in rapid retreat worldwide, notwithstanding a few complicated cases.
40 “IPCC does not represent a scientific consensus” The IPCC summarizes the recent research by leading scientific experts.
41 “Extreme weather isn’t caused by global warming” Extreme weather events are being made worse by global warming.
42 “CO2 is not a pollutant” Excess CO2 emissions will lead to hotter conditions that will stress and even kill crops.
43 “There’s no correlation between CO2 and temperature” There is long-term correlation between CO2 and global temperature; other effects are short-term.
44 “Greenland is gaining ice” Greenland on the whole is losing ice, as confirmed by satellite measurement.
45 “CO2 was higher in the past” While CO2 was higher in the past, the sun was cooler.
46 “Scientists can’t even predict weather” Weather and climate are different; climate predictions do not need weather detail.
47 “There’s no tropospheric hot spot” We see a clear “short-term hot spot” – there’s various evidence for a “long-term hot spot”.
48 “Neptune is warming” And the sun is cooling.
49 “Jupiter is warming” Jupiter is not warming, and anyway the sun is cooling.
50 “It’s Pacific Decadal Oscillation” The PDO shows no trend, and therefore the PDO is not responsible for the trend of global warming.
51 “CO2 effect is saturated” Direct measurements find that rising CO2 is trapping more heat.
52 “Pluto is warming” And the sun has been recently cooling.
53 “Greenland ice sheet won’t collapse” When Greenland was 3 to 5 degrees C warmer than today, a large portion of the Ice Sheet melted.
54 “Volcanoes emit more CO2 than humans” Humans emit 100 times more CO2 than volcanoes.
55 “Animals and plants can adapt to global warming” Global warming will cause mass extinctions of species that cannot adapt on short time scales.
56 “Medieval Warm Period was warmer” Globally averaged temperature now is higher than global temperature in medieval times.
57 “CO2 measurements are suspect” CO2 levels are measured by hundreds of stations across the globe, all reporting the same trend.
58 “It’s the ocean” The oceans are warming and moreover are becoming more acidic, threatening the food chain.
59 “It’s El Niño” El Nino has no trend and so is not responsible for the trend of global warming.
60 “Arctic sea ice is back to normal” Thick arctic sea ice is in rapid retreat.
61 “Less than half of published scientists endorse global warming” Around 95% of climate experts agree that humans are causing global warming.
62 “Dropped stations introduce warming bias” If the dropped stations had been kept, the temperature would actually be slightly higher.
63 “Solar Cycle Length proves its the sun” The sun has not warmed since 1970 and so cannot be driving global warming.
64 “It’s aerosols” Aerosols have been masking global warming, which would be worse otherwise.
65 “It’s microsite influences” Microsite influences on temperature changes are minimal; good and bad sites show the same trend.
66 “CO2 has a short residence time” Excess CO2 from human emissions has a long residence time of over 100 years
67 “It’s a climate regime shift” There is no evidence that climate has chaotic “regimes” on a long-term basis.
68 “2nd law of thermodynamics contradicts greenhouse theory” The 2nd law of thermodynamics is consistent with the greenhouse effect which is directly observed.
69 “Humans are too insignificant to affect global climate” Humans are small but powerful, and human CO2 emissions are causing global warming.
70 “It’s not happening” Recent global warming is occurring and is due to humans.
71 “Greenhouse effect has been falsified” The greenhouse effect is standard physics and confirmed by observations.
72 “It’s land use” Land use plays a minor role in climate change, although carbon sequestration may help to mitigate.
73 “The science isn’t settled” That human CO2 is causing global warming is known with high certainty & confirmed by observations.
74 “2009-2010 winter saw record cold spells” A cold day in Chicago in winter has nothing to do with the trend of global warming.
75 “It’s methane” Methane plays a minor role in global warming but could get much worse if permafrost starts to melt.
76 “500 scientists refute the consensus” Around 95% of climate experts agree that humans are causing global warming.
77 “Mike’s Nature trick to ‘hide the decline'” Michael Mann was quoted out of context, and nothing was hidden.
78 “IPCC were wrong about Himalayan glaciers” Glaciers are in rapid retreat worldwide, despite 1 error in 1 paragraph in a 1000 page IPCC report.
79 “Ocean acidification isn’t serious” Past history shows that when CO2 rises quickly, there was mass extinctions of coral reefs.
80 “Sea level rise predictions are exaggerated” Sea level rise is now increasing faster than predicted due to unexpectedly rapid ice melting.
81 “Naomi Oreskes’ study on consensus was flawed” Benny Peisner, the Oreskes critic, retracted his criticism.
82 “Phil Jones says no global warming since 1995” Phil Jones was misquoted.
83 “Ice isn’t melting” Ice is melting at an accelerating rate at both poles and in glaciers all over the world.
84 “CO2 is coming from the ocean” The ocean is absorbing massive amounts of CO2, and is becoming more acidic as a result.
85 “It’s not us” Multiple sets of independent observations find a human fingerprint on climate change.
86 “CO2 is not increasing” CO2 is increasing rapidly, and is reaching levels not seen on the earth for millions of years.
87 “It’s albedo” Albedo change in the Arctic, due to receding ice, is increasing global warming.
88 “Record snowfall disproves global warming” Warming leads to increased evaporation and precipitation, which falls as increased snow in winter.
89 “Hansen’s 1988 prediction was wrong” Jim Hansen had several possible scenarios; his mid-level scenario B was right.
90 “Lindzen and Choi find low climate sensitivity” Lindzen and Choi’s paper is viewed as unacceptably flawed by other climatologists.
91 “The sun is getting hotter” The sun’s output has just oscillated since 1970 with a slight cooling trend.
92 “Solar cycles cause global warming” Over recent decades, the sun has been slightly cooling & is irrelevant to recent global warming.
93 “Springs aren’t advancing” Hundreds of flowers across the UK are flowering earlier now than any time in 250 years.
94 “Over 31,000 scientists signed the OISM Petition Project” The ‘OISM petition’ was signed by only a few climatologists.
95 “Water levels correlate with sunspots” This detail is irrelevant to the observation of global warming caused by humans.
96 “IPCC were wrong about Amazon rainforests” The IPCC statement on Amazon rainforests was correct, and was incorrectly reported in some media.
97 “Climate is chaotic and cannot be predicted” Weather is chaotic but climate is driven by Earth’s energy imbalance, which is more predictable.
98 “Water vapor in the stratosphere stopped global warming” This possibility just means that future global warming could be even worse.
99 “Scientists retracted claim that sea levels are rising” The paper in question was misquoted.
100 “Mauna Loa is a volcano” The global trend is calculated from hundreds of CO2 measuring stations and confirmed by satellites.
101 “CO2 is not the only driver of climate” CO2 is the main driver of climate change.
102 “Trenberth can’t account for the lack of warming” Trenberth is talking about the details of energy flow, not whether global warming is happening.
103 “CO2 was higher in the late Ordovician” The sun was much cooler during the Ordovician.
104 “Southern sea ice is increasing” Antarctic sea ice has grown in recent decades despite the Southern Ocean warming at the same time.
105 “Melting ice isn’t warming the Arctic” Melting ice leads to more sunlight being absorbed by water, thus heating the Arctic.
106 “Global temperatures dropped sharply in 2007” But global temperatures rose sharply in 2009, to the second hottest level.
107 “Tree-rings diverge from temperature after 1960” This is a detail that is complex, local, and irrelevant to the observed global warming trend.
108 “Hulme says IPCC consensus was phoney” Ironically, it’s those who are mispresenting Hulme’s paper that are the ones being misleading.
109 “It’s CFCs” CFCs contribute at a small level.
110 “A drop in volcanic activity caused warming” Volcanoes have had no warming effect in recent global warming – if anything, a cooling effect.
111 “CO2 emissions do not correlate with CO2 concentration” That humans are causing the rise in atmospheric CO2 is confirmed by multiple isotopic analyses.
112 “It’s global brightening” This is a complex aerosol effect with unclear temperature significance.
113 “Warming causes CO2 rise” Recent warming is due to rising CO2.
114 “It’s ozone” Ozone has only a small effect.
115 “It’s satellite microwave transmissions” Satellite transmissions are extremely small and irrelevant.
116 “We didn’t have global warming during the Industrial Revolution” CO2 emissions were much smaller 100 years ago.
117 “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.
118 “Antarctica is too cold to lose ice” Glaciers are sliding faster into the ocean because ice shelves are thinning due to warming oceans.

 

Many thanks to Dr. Jan Dash, Director of the UU-UNO’s Climate Portal for writing many of the one line responses in ‘What the Science Says’, with some edits by John Cook.

great cheat sheet – get the iPhone app

Advertisements

What do you think about what I wrote?

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s