The Extinction Rebellion hysteria vs. climate science

by Fabius Maximus

Summary: The Extinction Rebellion and the Green New Deal are the next stage in the Left’s manipulation of the public’s fears, with the complicit silence of climate scientists. Here is what the IPCC’s AR5 says about fears of extinction for other species, and humanity.

Climate disaster: man walking across a parched ruined land
ID 25163217 © Ben Goode | Dreamstime.

Climate hysteria goes mainstream. Climate scientists remain silent.

The Extinction Rebellion – “This is an emergency.”

If Politicians Can’t Face Climate Change, Extinction Rebellion Will” by David Graeber (prof anthropology at the LSE) in a NYT op-ed – “A new movement is demanding solutions. They may just be in time to save the planet.” Also see “Extinction Rebellion and Momentum join forces on climate crisis” by Martha Busby at The Guardian.

Rep. Alexandria Ocasio-Cortez (D-NY) to interviewer Ta-Nehisi Coates at an “MLK Now” event in New York. Video here.

“Millennials and people, you know, Gen Z and all these folks that will come after us are looking up and we’re like: ‘The world is gonna end in 12 years if we don’t address climate change and your biggest issue is how are we gonna pay for it?’”

Planet Earth Is Doomed. How Do I Go On?” by Liza Featherstone at The Nation.

Andrew Samuels, a Jungian psychoanalyst and a professor at the University of Essex, tells me that therapists are increasingly hearing from patients who are deeply disturbed by climate change and are struggling to cope.”

We Need Radical Thinking on Climate Change” by Kevin Drum at Mother Jones – “{The Green New Deal} would only change the dates for planetary suicide by a decade or so.”

The Uninhabitable Earth” by David Wallace-Wells in New York Magazine – “Famine, economic collapse, a sun that cooks us: what climate change could wreak – sooner than you think.” Expanded into a book: The Uninhabitable Earth: Life After Warming.

The five ways the human race could be WIPED OUT because of global warming.” By Rod Ardehali at the Daily Mail. H/t to the daily links at Naked Capitalism. Promo for Falter: Has the Human Game Begun to Play Itself Out?, a book by Bill McKibben.

The media overflows with this stuff. It must be having a bad effect on America. There is almost no basis for these fears.

What warming can we expect?

The IPCC is the “gold standard” source showing the consensus of climate science. Here is the scariest graph from the Working Group I of the IPCC’s AR5: figure 12.5, a projection of global temperatures to 2300 under four scenarios (showing the increase from the 1986–2005 average).

Graph 12.5 from WGI of the IPCC's AR5: global temperatures to 2300

This is good science, although speculative. It is a weak basis for making public policy. First, the worst case scenario, RCP8.5, gets most of the attention – and dominates this picture. But it is either unlikely or impossible (also see this), as a good worst-case scenario should be. A table shows the result more clearly: Table SPM.2 of the Summary for Policymakers from Working Group I. The increase from the average of 1986–2005.

Table 2 of the Summary for Policymakers of Working Group I the IPCC's AR5: temperatures through 2100 by scenario

This shows the second weakness. The scenarios vary in likelihood – and in the results. The center two are the most likely, with projections through 2065 of 0.9 to 1.8°C. The world and humanity have experienced such swings during the past 3,000 years, and will again no matter what we do {even the carefully curated proxy reconstructions show a swings of ~1°C from 1000 to 1600 AD).

Third, climate models ability to make multi-decade predictions has not been validated, let alone proven by experience. Forecasts past 2065 rely on assumptions about factors that range from difficult to predict (e.g., global fertility) to unknowable (e.g., economic growth and technological progress). Forecasts past 2100 are imaginative exercises in modeling.

About the coming extinctions!

What does the Working Group II of AR5 say about extinctions? The Summary for Policymakers has a bold statement.

“Extinction risk is increased under all RCP scenarios, with risk increasing with both magnitude and rate of climate change.”

That is politics, meaningless rhetoric, not science. How much does the risk increase in each scenario, increasing from what to what level? Turn to the full report for answers. First, the good news – they give a rebuttal to the hysteria about the mass extinctions supposedly occurring now due to climate change (more details here).

“{O}nly a few recent species extinctions have been attributed as yet to climate change (high confidence) …” {p4.}

“While recent climate change contributed to the extinction of some species of Central American amphibians (medium confidence), most recent observed terrestrial species extinctions have not been attributed to climate change (high confidence).” {p44.}

“Overall, there is very low confidence that observed species extinctions can be attributed to recent climate warming, owing to the very low fraction of global extinctions that have been ascribed to climate change and tenuous nature of most attributions. (p300.)

Looking to the future.

Much of the report discusses possible results of 4°C warming above preindustrial levels – as of 2018, we are now ~1°C above that (likely 0.8 – 1.2°C). Supposedly an additional 0.5°C will prove disastrous.

WGI used a modern baseline, the average of 1986–2005, WGII uses preindustrial, defined as before 1750 (it occasionally uses preindustrial, such as for historical analysis). That has advantages for climate alarmists.

  • It measures warming from close to the trough of the coolest period for thousands of years.
  • There is no instrumental record for global temperatures in 1750.
  • Most valuable, it allows conflating natural warming from 1750 to WWII with anthropogenic warming (AGW) since WWII. To the public, all ill effects of this warming become effects of AGW.

What does WGII say about extinctions from AGW?

“Models project that the risk of species extinctions will increase in the future due to climate change, but there is low agreement concerning the fraction of species at increased risk, the regional and taxonomic distribution of such extinctions, and the timeframe over which extinctions could occur.” {p67.}

“Fischlin et al. (2007) found that 20 to 30% of the plant and animal species that had been assessed to that time were considered to be at increased risk of extinction if the global average temperature increase exceeds 2°C to 3°C above the preindustrial level with medium confidence, and that substantial changes in structure and functioning of terrestrial, marine, and other aquatic ecosystems are very likely under that degree of warming and associated atmospheric CO2 concentration. No time scale was associated with these findings.” (p278.)  Twenty-two times WGII cites this one paper published ten years ago, with no replication or follow-up.)

“All model-based analyses since AR4 broadly confirm this concern, leading to high confidence that climate change will contribute to increased extinction risk for terrestrial and freshwater species over the coming century. Most studies indicate that extinction risk rises rapidly with increasing levels of climate change, but some do not. …There is, however, low agreement concerning the overall fraction of species at risk, the taxa and places most at risk, and the time scale for climate change-driven extinctions to occur.” (p300.)

Those are scary but lack any meaningful detail, such as relationships between warming and extinction rates (scenarios, magnitudes, timing, etc).

“Within this century, magnitudes and rates of climate change associated with medium- to high-emission scenarios (RCP4.5, 6.0, and 8.5) pose high risk of abrupt and irreversible regional-scale change in the composition, structure, and function of terrestrial and freshwater ecosystems, including wetlands (medium confidence).” (p15.)

“From a global perspective, open ocean NPP {net primary productivity} will decrease moderately by 2100 under both low- (SRES B1 or RCP4.5) and high-emission scenarios (medium confidence; SRES A2 or RCPs 6.0, 8.5) …. However, there is limited evidence and low agreement on the direction, magnitude and differences of a change of NPP in various ocean regions and coastal waters projected by 2100 (low confidence).” (p135.)

“There is a high risk that the large magnitudes and high rates of climate change associated with low-mitigation climate scenarios (RCP4.5 and higher) will result within this century in abrupt and irreversible regional-scale change in the composition, structure, and function of terrestrial and freshwater ecosystems, for example in the Amazon (low confidence) and Arctic (medium confidence), leading to substantial additional climate change.” (p276.)

WGII discusses bad impacts on some specific kinds of creatures, such as corals. Nothing about extinction of humans. The 1,150 pages of WGII have a remarkable lack of specificity about what we can expect from the various scenarios.

AR5 describes the assessed likelihood of an outcome or a result: “virtually certain 99–100% probability, very likely 90–100%, likely 66–100%, about as likely as not 33–66%, unlikely 0–33%, very unlikely 0–10%, exceptionally unlikely 0–1%.”


The Left has incited hysteria about climate change for political gain (the Green New Deal is their maximum dreams given form). Climate scientists and their institutions have remained silent for years as the Left’s claims grew more extreme and less grounded in science. This is irresponsible, even malfeasance. It will not end well for anyone involved. Only one can win in the fight of the Extinction Rebellion vs. climate science.

An ignored warning from long ago, a path not taken

Here is a remarkable op-ed in the BBC: “Science must end climate confusion” by climate scientist Richard Betts, 11 January 2010. He cautions about scientists exaggerating or misrepresenting climate science “if it helps make the news or generate support for their political or business agenda.” Too bad they did not heed his warning.

Other posts about climate scientists’ culpability through silence

  1. About the corruption of climate science.
  2. The noble corruption of climate science – Falling prey to the Nobel Lie.
  3. A crisis of overconfidence in climate science.