"Our planet has just experienced three consecutive warmest years on record—2014, 2015, and 2016—which has made it difficult to find politicians who continue to deny the reality of global warming and climate change. However, denial of climate science has shifted to a new tactic: to claim that the indisputable heating of the planet is primarily a natural phenomenon, and that there is major uncertainty among scientists on the issue."
Deniers have picked a "new tactic" because of three warm years? I've been saying this for a decade or so.
"These assertions are false. Based on the evidence, more than 97% of climate scientists have concluded that human-caused climate change is happening; scientists’ “best estimate” is that ALL of the global warming since 1950 has been human-caused, primarily through an increase in carbon dioxide due to the burning of fossil fuels."
The link Masters gives does not go directly to any survey of climate scientists, but to an Anthropogenic Global Warm cheer-leading page. That page does, however, provide a link to support that claim, which states:"The number of papers rejecting AGW [Anthropogenic, or human-caused, Global Warming] is a miniscule proportion of the published research, with the percentage slightly decreasing over time. Among papers expressing a position on AGW, an overwhelming percentage (97.2% based on self-ratings, 97.1% based on abstract ratings) endorses the scientific consensus on AGW.”
Which casts into doubt Jeff Master's credibility as a straight shooter, or as a thinker. It should be obvious that a survey of published papers "expressing a position on AGW" is quite different from "any survey of climate scientists." Doesn't Masters recognize the difference? If not, he shouldn't be talking about science. If so, well go to Confession this week and tell your priest you've been fooling readers, Mr. Masters.
One simply cannot conclude from the fact that most published papers expressing an opinion support strong AGW (if they do, let us not concede that too readily), that most scientists believe in it. There may be systematic bias among journal editors. They may be afraid to publish against the alleged "consensus." Or most likely of all, the expressing of an opinion is a self-selecting act: scientists who are unsure, are unlikely to express their views in a paper.
What is certain, it that Master's claim does not follow from his (hidden behind two links) premises. He has misrepresented his sources.
"Many prominent members of the Trump administration, who all have ties to the fossil fuel industry, have been making false claims about scientists’ understanding that global warming is human-caused. For example:"
We recognize that as "ad hominem." These men may have ties to the devil (in fact three of them represented states that produce fossil fuels), that would not disprove their points.
"During his hearing in January 2017 to become the new EPA administrator, Scott Pruitt claimed: 'There is a diverse range of views regarding the key drivers of our changing climate among scientists.'”
And no doubt there is -- 'diversity of opinions" is one of the chief cliches in almost every field of scholarship. If opinions on so complex a matter were not "diverse," then something rotten would be found in the state of science.
But Pruitt also said, "the climate is changing, and human activity contributes to that in some manner." Forgot to quote that part, didn't you, Mr. Masters?
"Former Exxon-Mobil CEO Rex Tillerson, who is now President Trump’s Secretary of State, claimed in his confirmation hearing: 'I agree with the consensus view that combustion of fossil fuels is a leading cause for increased concentrations of greenhouse gases in the atmosphere. I understand these gases to be a factor in rising temperatures, but I do not believe the scientific consensus supports their characterization as the ‘key’ factor.”
Nor has Pruitt shown otherwise.
"On the February 21, 2014, edition of MSNBC’s The Daily Rundown, host Chuck Todd asked future Vice President Mike Pence if he was “convinced that climate change is man-made.” Pence responded: “I don't know that that is a resolved issue in science today.” Pence similarly stated on the May 5, 2009, edition of MSNBC’s Hardball that “I think the science is very mixed on the subject of global warming.”
- Rick Perry, Trump’s nominee for Secretary of Energy, told the Senate Energy and Natural Resources committee in January: “I believe the climate is changing. I believe some of it's naturally occurring and some of it is caused by man-made activity.”
Well good! Sounds like Trump has wisely appointed some people with proper scientific caution to key positions.
What sort of dingbat would say that none of the climate change was caused by natural cycles or events? That sort of statement really would cast doubt on a public official's good sense.
Figure 1. "Global annual temperatures up to the year 2015 (thin light red, with an 11-year moving average shown as a thick dark red line) have increased steadily, even though the total amount of energy from the sun (the annual Total Solar Irradiance, thin light blue, with an 11-year moving average shown as a thick dark blue line) has decreased slightly. Climate in past eras has seen many instances of global warming, which have been caused by an increase in heat-trapping gases like carbon dioxide or an increase in the amount of solar energy being absorbed by the Earth. Since solar energy cannot be to blame for the increase in global temperatures since 1950, scientists are confident that the steadily rising levels of heat trapping gases like carbon dioxide due to human activities is causing the observed global warming. Image credit: skepticalscience.com."
This is a kind of ink-blot test, it seems, or the "young and old women" sketch. I see a young woman -- what do you see?
What I see is a very slight increase in solar radiation -- about one part in 3000 -- from 1880 to 1960. Then it stays high until about 2000, as warming continues, until it drops over the past few years.
While I am not a climatologist, I would be surprised if solar radiation and CO2 were the only factors in determining atmospheric temperatures. But if I believed that those were the only factors (and I've seen many scientists name others), then I would say this graph seems to support the theory that solar radiation may be to blame for a good chunk of the warming. There are often lags between causes and effects, after all -- which is why December 21 is not the middle of winter, to pick an obvious example related to radiation, or why 12 noon is not usually the hottest time of day.
Let us consider some neglected background facts. Glaciers started melting in much of the world about the mid-1800s. (Including in the Mendenhall Valley outside of Juneau, where I went to school -- our home there had been covered by glaciers not too many decades before.) In the 19th Century -- and really, up until World War II -- carbon burning was a tiny fraction of what it is today. Hardly anyone had cars, and industrial output, even population, were fractional compared to today. Yet the globe was warming during those years -- years mostly left off this chart.
So clearly there was a lot of warming going on towards the left hand side of this chart, and beyond, little if any of which can be explained by AGW.
Shouldn't Masters have mentioned that?
"The best science says: ALL of the warming since 1950 is human-caused
"Based on the evidence, more than 97% of climate scientists have concluded that human-caused climate change is happening.
Masters gives the same fake link, which proves nothing of the sort.
"That’s about the same certainty with which scientists link smoking cigarettes to lung cancer."
This time Masters links to an article from Scientific American, which offers no such data.
"The latest 2013 Intergovernmental Panel on Climate Change (IPCC) report—the enormous consensus scientific summary of the science of climate change prepared once every six years--had this to say about the observed warming of Earth since 1950:
“The best estimate of the human-induced contribution to warming is similar to the observed warming over this period.”
"In other words, ALL of the observed warming after 1950 (0.6°C, 1.1°F) is due to humans. A total of 0.85°C (1.5°F) total global warming has been observed since 1880. The IPCC further quantified that human activity is extremely likely (at least 95% chance) to be responsible for more than half of Earth's temperature increase after 1950."
Masters conflates "best estimate" and "is similar to" with "all is." The IPCC is, to give it credit, rather more cautious. But even their estimate is consistent with most warming since, say, 1850 when the glaciers started retreating, being due to other causes.
And that has been my view for many years. Given the longer-term trend not since the 1950s but since the 1850s, and some respect for Occam, it seems to me likely that human activity has contributed between a third and a half of the global warming over the past 170 years.
Three more facts seem worth pondering.
First, the warming effect of CO2 is proportional to the square of its increase. In other words, the more you add, the less impact each unit of CO2 has in warming the atmosphere.
Second, rapid industrialization and the purchase of cars in the former "Third World" (including China and India) mean that CO2 release may increase rapidly enough to have some impact, despite (1).
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