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Memo to Jeb Bush: denying human-caused global warming is ignorant

Posted on 27 May 2015 by dana1981

In a campaign event last week, Republican presidential frontrunner Jeb Bush exhibited Stage 2 climate denial, saying (video available here),

Look, first of all, the climate is changing. I don’t think the science is clear what percentage is man-made and what percentage is natural. It’s convoluted. And for the people to say the science is decided on, this is just really arrogant, to be honest with you. It’s this intellectual arrogance that now you can’t even have a conversation about it.

The Politics

Unfortunately, denial of human-caused global warming may be a prerequisite for any viable Republican presidential candidate. Conservative and Tea Party Republicans are the one group of American voters among whom Stage 2 climate denial is the majority position, but they’re also the group that most reliably votes in GOP primary elections. 

In American politics, a candidate first has to win a primary election before reaching the national ballot. For Republicans, that means appealing to conservatives. It’s not clear that a Republican presidential candidate can accept climate science and run a viable primary campaign.

The Science

Nevertheless, the scientific evidence supporting human-caused global warming is just as strong as the evidence linking smoking and lung cancer. Last year, the IPCC stated with 95% confidence that humans are the main cause of the global warming that’s occurred since 1950. Their best estimate is that we’re responsible for about 100% of the warming during the past six decades.

Gavin Schmidt, Director of the NASA Goddard Institute for Space Studies, put together this graph showing what’s known as the probability density function of the human contribution to global warming since 1950, based on the IPCC report.


The probability density function for the fraction of warming attributable to human activity (derived from Fig. 10.5 in IPCC AR5). The bulk of the probability is far to the right of the “50%” line, and the peak is around 110%. Created by Gavin Schmidt.

As the figure shows, natural factors have most likely caused a slight cooling since 1950, meaning that human factors are most likely responsible for all the warming we’ve seen and then some (110%). The odds that natural factors are responsible for the majority of global warming over the past six decades is virtually zero.

This assessment is based on multiple lines of evidence. There are climate model simulations, which can’t account for the observed warming without a dominant influence from the increased greenhouse effect. There are “fingerprints” of human-caused global warming, which are effects we expect to see in the patterns of climate change if those changes are due to the increased greenhouse effect. I explain some of these in one of my Denial101x lectures.

 Denial101x lecture 3.4.3 by Dana Nuccitelli.

Basic physics is perhaps the most convincing piece of evidence behind human-caused global warming. Long-term global warming and cooling events are caused by changes in the Earth’s energy balance. If there’s more incoming than outgoing energy, the planet warms, and vice-versa. Natural variability, like ocean cycles, only causes short-term temperature changes.

Since 1950, the Earth has had a large and growing energy imbalance due almost entirely to the human-caused increased greenhouse effect. There’s actually been a slight decrease in incoming energy from the sun during that time, an hence a slight solar cooling effect. 

Overall, the energy imbalance (a.k.a. radiative forcing) from the increased greenhouse effect has caused more warming than we’ve observed, having been offset by some cooling from other human pollutants (aerosols) blocking sunlight, as shown in this figure from the IPCC report.

IPCC AR5 forcings

Assessed likely ranges (whiskers) and their mid-points (bars) for warming trends over the 1951–2010 period from well-mixed greenhouse gases (GHG), other anthropogenic forcings (OA; including the cooling effect of aerosols and the effect of land use change), combined anthropogenic forcings (ANT), natural forcings (NAT), and natural internal climate variability. The observed surface temperature change is shown in black, with the 5 to 95% uncertainty range due to observational uncertainty. Source: IPCC AR5 Figure 10.5.

And of course because of these many lines of overwhelming evidence, there’s a97% consensus among climate scientists and in their peer-reviewed climate research on human-caused global warming. There are a few outlier climate scientists who disagree, like Judith Curry, who incorrectly claimed “Jeb gets it exactly right,” but these contrarians are a slim minority. 

As the evidence clearly shows, Jeb got it exactly wrong. It’s not arrogant to accept the overwhelming preponderance of scientific evidence, basic physics, or a 97% expert consensus; rather, it’s ignorant to deny it. 

The Policies

At the same campaign event, Bush ironically claimed,

I think, as conservatives, we should embrace innovation, embrace technology, embrace science; it’s the source of a lot more solutions than any government-imposed idea.

Yes, the conservative presidential frontrunner suggested that conservatives should embrace science just a few moments after he rejected the science on global warming. Nevertheless, a candidate’s favored policies are more important than his acceptance or rejection of science. Unfortunately, while Bush suggested that conservatives embrace technology, he only specifically supported natural gas,

We’ve had a decrease [in carbon emissions], a pretty significant decrease and it will continue on, not because of Barack Obama, but because of the energy revolution, because of free-enterprise, because of private property rights because of American innovation has created a combination of two existing technologies: hydraulic fracking and horizontal drilling has created an explosion of lower carbon energy that is being used to replace higher carbon energy.

Research has shown that at best, natural gas can only act as a (short) bridge fuelduring the transition to low-carbon energy sources if we want to avoid dangerous global warming, and in fact it might not even be a suitable bridge. In any case, “we should embrace innovation, embrace technology” is not a concrete policy platform. 

Bush clearly opposes the legally-mandated government regulations of carbon pollution enacted by the Obama administration. However, it’s the Democratic Party that’s supported free-market carbon pricing policy alternatives, evenoffering small-government revenue-neutral compromise legislation. While the Republican Party and the fossil fuel industry have tried to repeal the government regulations, they haven’t accepted that compromise offer or proposed any alternative policies of their own.

Bush also tried to pass the buck, claiming that other countries are responsible for solving the problem,

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Comments 1 to 10:

  1. Slightly OT but does anyone know about Dr Alan Carlin's book Environmentalism Gone Mad? Apparently he is a 38 yr vet at the EPA and a Sierra Club chapter chairman, an aquaintance said I should read, is he legit?

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  2. Alan Carlin is a PhD economist, though he does have a Bachelor's in physics.  His contentions are straight from the denialist's playbook, including the disproof of CO2 as a global warming cause because temperatures decreased in the six years from 2002 to 2008 (he claimed), CO2 rise follows temperature rise, . . . .  DeSmogBlog has a profile.

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  3. Interesting, wonder what motivates a life long EPA/enviro to publish this?

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  4. RM,

    "what motivates a life long EPA/enviro to publish this"

    Barred some sort of material reward, most likely an emotional reaction to something that happened to him. I suspect that might have been the case also for J. Curry. We are emotional beings. It served us well for the few million years during which the species lived in natural conditions. For more advanced thinking, emotions have to be more carefully managed and one has to always keep in mind that they can affect our judgment to the point of rendering it inoperative. They can also be useful.

    Other things have profound influences on us. The initial conditionings applied to young people duting their formative years make an indelible mark. I have read articles by religiously raised geologists who could never shake their early conditioning from a rather fundamentalist church, and lived in a constant state of cognitive dissonance. They were having to deal with geological time scales on one hand, while the conviction had been drilled in them at a young age that the Earth was 6000 years old, a conviction that carried a high emotional charge. Humans are best equipped and worst equipped to investigate reality...

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  5. I know something about influences, I was raised in a SDA home and it does take much time and thought to rid oneself of the dogma, however I find myself today as a devout libertarian and skeptical of all claims. My motto is "show me, don't tell me".

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  6. More advanced thinking could only ever be done by a few individuals anyway- by definition-  thus we can now see emotion was always able to inspire or crush the individual. The only difference in higher thinking abilities between us and the people of eons ago is education gained via through eons of lesser and lesser non-descript method toward matters.

    The elite and the proles depend on a bright spark from the masses who number 90%: then it all changes and the next revolution of thought and/or action is awaited upon.

    Emotional IQ comes down to panic control: pilots and so forth concentrate on such skill sets whereas most don't. Those who succeed in any endevour can control panic to a greater degree than those that don't.

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  7. Interestingly, recent polls show that even 48% of Republicans favor taking actions to combat global warming... but virtually every GOP politician at the national level still denies that we can do anything about it. The problem is that the half of GOP voters who reject reality are much more vocal, and determined to do nothing about global warming.

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  8. I am in full agreement with the ad-hominem rule on this site. Let's have at least one place on the Internet where the discussion doesn't descend into name calling and personal attacks.

    But I would say this; While we need more politicians to embrace the science, I am almost glad that Jeb denies climate science because I truly want to support a pro-climate candidate yet I have many other reasons why I would still not be able to support Jeb.

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  9. Well CB you have to understand that they don't care what most people want, even those people who vote for them

    What they care about is the Corporations and Billionaires that fund their propaganda campaigns to the hilt .... What they say goes, it's as simple as that.

    I'm here at Ground Zero for Presidential Politics (Iowa) and it's amazing how many GOP candidates are climbing out of the GOP Clown Car this year and they all pretty much sazy the exact same thing excpet for Rand Paul and his only difference is about the debacle of the Iraq War and the debacle caused by it in the Middle East today.

    You can cut the Cognitive Dissonence with a knife it's so thick here are on one hand they deny Global Warming and on the other hand must support the most Subsidized energy source in the US today, Ethanol based on it lowering CO2 .... Which doesn't really matter because CO2 doesn't cause Global Warming ... but we still need it anyway because it lowers CO2 (Classic circular thinking) 

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  10. longjohn119, actually it is 'not that bad'.

    Yes, big donors have a huge influence on politics in the US, especially with the GOP. However, it is simply false that politicians don't care what their voters want. You can be quite certain that if 99% of GOP voters wanted action on climate change that the national GOP candidates would not be loudly proclaiming that it doesn't exist. They do still need those people to vote for them to get elected. Yes, they might then very well turn around and do nothing about the issue once they were in office (c.f. GOP constant screaming about budget deficits... coupled with massive deficit increases whenever they are in power). However, ending the false public 'debate' on AGW would still constitute progress... because if it weren't a litmus test for the support of a large percentage of GOP voters then a few GOP politicians who believe in doing something about the problem could more easily slip through the screening process of the monied interests.

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