How to Talk to a Climate Skeptic: Responses to the most common skeptical arguments on global warming
Below is a complete listing of the articles in “How to Talk to a Climate Skeptic,” a series by Coby Beck containing responses to the most common skeptical arguments on global warming. There are four separate taxonomies; arguments are divided by:
Individual articles will appear under multiple headings and may even appear in multiple subcategories in the same heading.
Stages of Denial
- There’s nothing happening
- Inadequate evidence
- Contradictory evidence
- It’s cold today in Wagga Wagga
- Antarctic ice is growing
- The satellites show cooling
- What about mid-century cooling?
- Global warming stopped in 1998
- But the glaciers are not melting
- Antarctic sea ice is increasing
- Observations show climate sensitivity is not very high
- Sea level in the Arctic is falling
- Some sites show cooling
- No consensus
- We don’t know why it’s happening
- Models don’t work
- Prediction is impossible
- We can’t be sure
- Climate change is natural
- It happened before
- It’s part of a natural change
- Current global warming is just part of a natural cycle
- Mars and Pluto are warming too
- CO2 in the air comes mostly from volcanoes
- The null hypothesis says global warming is natural
- Climate is always changing
- Natural emissions dwarf human emissions
- The CO2 rise is natural
- We are just recovering from the LIA
- It’s not caused by CO2
- Climate scientists dodge the subject of water vapor
- Water vapor accounts for almost all of the greenhouse effect
- There is no proof that CO2 is causing global warming
- Mars and Pluto are warming too
- CO2 doesn’t lead, it lags
- What about mid-century cooling?
- Geological history does not support CO2’s importance
- Historically, CO2 never caused temperature change
- It’s the sun, stupid
- Climate change is not bad
- The effects are good
- Climate change can’t be stopped
- Too late
- It’s someone else’s problem
- Economically infeasible
Scientific Topics
- Temperature
- There is no evidence
- The temperature record is simply unreliable
- One hundred years is not enough
- Current global warming is just part of a natural cycle
- What’s wrong with warmer weather?
- It’s cold today in Wagga Wagga
- Warming is due to the Urban Heat Island effect
- The satellites show cooling
- Global warming stopped in 1998
- They predicted global cooling in the 1970s
- One record year is not global warming
- Some sites show cooling
- Cryosphere
- Oceans
- Modeling
- Climate forcings
- Solar influences
- Greenhouse gases
- Climate scientists dodge the subject of water vapor
- Water vapor accounts for almost all of the greenhouse effect
- There is no proof that CO2 is causing global warming
- CO2 doesn’t lead, it lags
- CO2 in the air comes mostly from volcanoes
- What about mid-century cooling?
- Geological history does not support CO2’s importance
- Natural emissions dwarf human emissions
- Mauna Loa is a volcano
- The CO2 rise is natural
- Historically, CO2 never caused temperature change
- The US is a net CO2 sink
- Observations show climate sensitivity is not very high
- Aerosols
- Paleo climate
- Holocene
- Ice ages
- Geologic history
- Scientific process
- Global warming is a hoax
- There is no proof that CO2 is causing global warming
- There is no consensus
- The null hypothesis says global warming is natural
- Position statements hide debate
- If we can’t understand the past, how can we understand the present?
- The scientists aren’t even sure
- Consensus is collusion
- Peiser refuted Oreskes
Types of Argument
- Uninformed
- Misinformed
- It was warmer during the Holocene Climatic Optimum
- The medieval warm period was just as warm as today
- Antarctic ice is growing
- CO2 in the air comes mostly from volcanoes
- Greenland used to be green
- The satellites show cooling
- Natural emissions dwarf human emissions
- It’s the sun, stupid
- The U.S. is a net CO2 sink
- But the glaciers are not melting
- Antarctic sea ice is increasing
- They predicted global cooling in the 1970s
- Vineland was full of grapes
- Cherry Picking
- Urban Myths
- FUD
- The temperature record is simply unreliable
- Glaciers have always grown and receded
- Climate scientists dodge the subject of water vapor
- Water vapor accounts for almost all of the greenhouse effect
- Current global warming is just part of a natural cycle
- Kyoto is a big effort for almost nothing
- Mars and Pluto are warming too
- It’s cold today in Wagga Wagga
- CO2 doesn’t lead, it lags
- There is no consensus
- Antarctic ice is growing
- Warming is due to the Urban Heat Island effect
- We can’t even predict the weather next week
- Chaotic systems are not predictable
- What about mid-century cooling?
- The null hypothesis says global warming is natural
- Geological history does not support CO2’s importance
- Climate is always changing
- Natural emissions dwarf human emissions
- Mauna Loa is a volcano
- Global warming is nothing new!
- The CO2 rise is natural
- The hockey stick is broken
- Historically, CO2 never caused temperature change
- The models don’t have clouds
- Global warming stopped in 1998
- If we can’t understand the past, how can we understand the present?
- If aerosols are blocking the sun, the south should warm faster
- The scientists aren’t even sure
- Antarctic sea ice is increasing
- Peiser refuted Oreskes
- Vineland was full of grapes
- Observations show climate sensitivity is not very high
- Sea level in the Arctic is falling
- We are just recovering from the LIA
- Non Scientific
Levels of Sophistication
- Silly
- Naive
- One hundred years is not enough
- Glaciers have always grown and receded
- Why should the U.S. join Kyoto when China and India haven’t?
- It’s cold today in Wagga Wagga
- CO2 in the air comes mostly from volcanoes
- We can’t even predict the weather next week
- We can not trust unproven computer models
- The satellites show cooling
- Natural emissions dwarf human emissions
- The models don’t have clouds
- Global warming stopped in 1998
- It’s the sun, stupid
- If we can’t understand the past, how can we understand the present?
- The scientists aren’t even sure
- Vineland was full of grapes
- Some sites show cooling
- Specious
- The temperature record is simply unreliable
- Climate scientists dodge the subject of water vapor
- There is no proof that CO2 is causing global warming
- Current global warming is just part of a natural cycle
- It was warmer during the Holocene Climatic Optimum
- The medieval warm period was just as warm as today
- What’s wrong with warmer weather?
- Kyoto is a big effort for almost nothing
- CO2 doesn’t lead, it lags
- There is no consensus
- Antarctic ice is growing
- Warming is due to the Urban Heat Island effect
- Greenland used to be green
- What about mid-century cooling?
- The null hypothesis says global warming is natural
- Geological history does not support CO2’s importance
- Climate is always changing
- Global warming is nothing new!
- The CO2 rise is natural
- Historically, CO2 never caused temperature change
- Hansen has been wrong before
- Position statements hide debate
- But the glaciers are not melting
- If aerosols are blocking the sun, the south should warm faster
- Antarctic sea ice is increasing
- Consensus is collusion
- They predicted global cooling in the 1970s
- Peiser refuted Oreskes
- Vineland was full of grapes
- Scientific
Stories in this series:
‘There is no evidence’ — Yes, there is
(Part of the How to Talk to a Climate Skeptic guide) Objection: Despite what the computer models tell us, there is actually no evidence of significant global warming. Answer: Global warming is not an output of computer models; it is a conclusion based on observations of a great many global indicators. By far the most straightforward evidence is the actual surface temperature record. While there are places -- in England, for example -- that have records going back several centuries, the two major global temperature analyses can only go back around 150 years due to their requirements for both quantity and distribution of temperature recording stations. These are the two most reputable globally and seasonally averaged temperature trend analyses:
‘Mauna Loa is a volcano’ — CO2 rise is measured on top of a volcano!
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: CO2 levels are recorded on top of Mauna Loa ... a volcano! No wonder the levels are so high. (image courtesty of Global Warming Art)
‘Warming is due to the Urban Heat Island effect’ — No, it isn’t
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: The apparent rise of global average temperatures is actually an illusion due to the urbanization of land around weather stations, the Urban Heat Island effect.
‘One hundred years is not enough’–Yes it is
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: One hundred and some years of global surface temperatures is not long enough to draw any conclusions from or worry about anyway. Answer: The reliable instrumental record only goes back 150 years in the CRU analysis, 125 in the NASA analysis. This is a simple fact that we are stuck with. 2005 was the warmest year recorded in that period according to NASA, a very close second according to CRU. Because of this limit, it is not enough to say today that these are the warmest years since 150 years ago, rather one should say 'at least': 1998 and 2005 are the warmest two years in at least the last 150.
‘The scientists aren’t even sure’ — No scientist ever is
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Even the scientists don't know that the climate is changing more than normal and if it's our fault or not. If you read what they write it is full of "probably," "likely," "evidence of" and all kinds of qualifiers. If they don't know for sure, why should we worry yet?
‘One record year is not global warming’–Luckily, there are plenty more years to consider
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: So 2005 was a record year. Records are set all the time. One really warm year is not global warming. Answer: This is actually not an unreasonable point -- single years taken by themselves can not establish or refute a trend. So 2005 being the hottest globally averaged temperature on record is not convincing. Then how about:
‘Glaciers have always grown and receded’–A few glaciers melting does not mean global warming
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: A few glaciers receding today is not proof of global warming. Glaciers have grown and receded differently in many times and places.
‘The temperature record is unreliable’–But temperature trends are clear and widely corroborated
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: The surface temperature record is full of assumptions, corrections, differing equipment and station settings, changing technology, varying altitudes, and more. It is not possible to claim we know what the "global average temperature" is, much less determine any trend. The IPCC graphs only say what the scientists want them to say.
‘It’s cold today in Wagga Wagga’–Weather and climate are different
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: It was way colder than normal today in Wagga Wagga, proof that there is no global warming. Does this even deserve an answer? If we must ...
‘The satellites show cooling’–No, they don’t
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Satellite readings, which are much more accurate, show that the earth is in fact cooling. I wonder how long before this one stops coming up?
‘What about mid-century cooling?’–No one said CO2 is the only climate influence
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: There was global cooling in the '40s, '50s, and '60s, even while human greenhouse-gas emissions were rising. Clearly, temperature is not being driven by CO2.
‘Antarctic ice is growing’–Well, probably not, but even if it were, we are not off the hook
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: The Antarctic ice sheets are actually growing, which wouldn't be happening if global warming were real. Answer: There are two distinct problems with this argument. First, any argument that tries to use a regional phenomenon to disprove a global trend is dead in the water. Anthropogenic global warming theory does not predict uniform warming throughout the globe. We need to assess the balance of the evidence.
‘Global warming stopped in 1998′–Only if you flagrantly cherry pick
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Global temperatures have been trending down since 1998. Global warming is over. Answer: At the time, 1998 was a record high year in both the CRU and the NASA GISS analyses. In fact, it blew away the previous record by .2 degrees C. (That previous record went all the way back to 1997, by the way!) According to NASA, it was elevated far above the trend line because 1998 was the year of the strongest El Nino of the century. Choosing that year as a starting point is a classic cherry pick and demonstrates why it is necessary to remove chaotic year-to year-variability (aka: weather) by smoothing out the data. Looking at CRU's graph below, you can see the result of that smoothing in black.
‘But the glaciers are not melting’–Except … they are!
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Sure, some glaciers are melting. But if you look at the studies, most of those for which we have data are growing. Answer: This is simply not true, rumors on "the internets" aside. The National Snow and Ice Data Centre and their State of the Cryosphere division, on their Glacial Balance page, report an overall accelerating rate of glacial mass loss. The World Glacier Monitoring Service has similar findings, the most recent data coming from 2004.
‘Antarctic sea ice is increasing’–Yes, but …
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Sure, sea ice is shrinking in the Arctic, but it is growing in the Antarctic. Sounds like natural fluctuations that balance out in the end. Answer: Overall, it is true that sea ice in the Antarctic is increasing. Around the peninsula, where there is a lot of warming [PDF], the ice is retreating. This is the area of the recent and dramatic Larsen B and Ross ice shelf breakups. But the rest of the continent has not shown any clear warming or cooling and sea ice has increased over the last decade or so. This is not actually a big surprise.
‘Sea level in the Arctic is falling’–Sea level is a surprisingly complicated thing
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: According to the latest state-of-the-art satellite measurements from over the Arctic, sea levels are falling! Guess all that ice isn't melting after all. Answer: Yes, a new study using Europe's Space Agency's ERS-2 satellite has determined that over the last 10 years, sea level in the Arctic Ocean has been falling at an average rate of about 2 mm/year. This is very new and very interesting news, though it is preliminary and not published in any peer-reviewed journals yet. But even if these results hold up to time and scrutiny, it is not evidence that globally sea levels are not rising, because they are.
‘Climate sensitivity is not very high’–Thermal inertia of the oceans means the jury is still out
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Taking into account the logarithmic effect of CO2 on temperature, the 35 percent increase we have already seen in CO2 concentrations represents about three-quarters of the total forcing to be expected from a CO2 doubling. Since we have warmed about 0.7 degrees Celsius so far, we should only expect about 0.3 degrees more for a doubling from pre-industrial levels, so about 1 degree total, not 3 degrees as the scientists predict. Clearly the climate model sensitivity to CO2 is much too high. Answer: Even without addressing the numbers in this argument, there is a fundamental flaw in its reasoning.
‘Some sites show cooling’–But you can’t draw global conclusions from individual sites
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Some stations, in the U.S. for example, show cooling trends. If there were really global warming, it would be warming everywhere. Answer: Global warming is the long-term increase in globally and seasonally averaged surface temperatures. It is not the case, nor is it expected, that all regions on the planet, let alone all weather stations, will show the same changes in temperature or rainfall patterns. Many stations have shown cooling, and some small regions have shown modest cooling as well. This does not invalidate global warming theory; it is merely the result of regional variation, and an example of how varied and complex the climate system is. (source: NASA)
‘Global warming is a hoax’–I wish James Inhofe were just a hoax …
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Global warming is a hoax perpetrated by environmental extremists and liberals who want an excuse for more big government (and/or world government via the U.N.). This is a common line, regardless of how ridiculous it is, so it should not go unanswered. Answer: Here is a list of organizations that accept anthropogenic global warming as real and scientifically well-supported:
‘There is no consensus’–If this is not consensus, what would consensus look like?
(Part of the How to Talk to a Global Warming Skeptic guide) Objection: Climate is complicated and there are lots of competing theories and unsolved mysteries. Until this is all worked out, one can't claim there is consensus on global warming theory. Until there is, we should not take any action. This is similar to the "global warming is a hoax" article, but at least here we can narrow down just what the consensus is about. Answer: Sure there are plenty of unsolved problems and active debates in climate science. But if you look at the research papers coming out these days, the debates are about things like why model predictions of outgoing longwave radiation at the top of the atmosphere in tropical latitudes differ from satellite readings, or how the size of ice crystals in cirrus clouds affect the amount of incoming shortwave reflected back into space, or precisely how much stratospheric cooling can be attributed to ozone depletion rather than an enhanced greenhouse effect. No one in the climate science community is debating whether or not changes in atmospheric CO2 concentrations alter the greenhouse effect, or if the current warming trend is outside of the range of natural variability, or if sea levels have risen over the last century. This is where there is a consensus.
