Losing Earth & Hothouse Earth

Flash Droughts Are Becoming More Common.

I wanted to bookmark two well-written articles on climate change that contain useful information. Nothing better than a blog post for making a record.

Here is a link to download Trajectories of the Earth System in the Anthropocene. The article describes the apocalypse that will probably occur if Earth warms by two degrees Celsius.

“Our study suggests that human-induced global warming of two degrees Celsius may trigger other Earth system processes, often called “feedbacks,” that can drive further warming – even if we stop emitting greenhouse gases,” –Will Steffen, lead author of the study published in the journal PNAS.

The article is catching lots of attention, but not as much as the Sunday NY Times article by Nathaniel Rich. All the major news media are discussing that article: Losing Earth; the Decade We Almost Stopped Climate Change.

“Like most human questions, the carbon-dioxide question will come down to fear. At some point, the fears of young people will overwhelm the fears of the old. Some time after that, the young will amass enough power to act. It will be too late to avoid some catastrophes, but perhaps not others” — Nathaniel Rich, NYT.

Reading Losing Earth followed by Trajectories provides excellent context for the need for climate action.

Helping Wildlife Survive the Sixth Mass Extinction

Preserving Critical Habitats Will Help More Wildlife Survive

This morning, an article by Andrew Suggitt (How wildlife will keep cool. . . .) made me think again about refugia. Earlier, I concluded that unlike ice ages, global warming would leave no refugia in which pockets of wildlife would survive. I was picturing a pervasive atmospheric impact instead of a discontinuous physical impact by tongues of glacial ice. I was wrong. The best habitats for wildlife, the ones along streams, in deep shaded canyons, and those in areas of diverse topography will sustain more wildlife as climate changes. Preserving those habitats is an essential goal for wildlife conservation.

Rick Turley. Approaching Wind River Canyon.

Unfortunately, the best habitats for wildlife are the most desirable for humans. Worldwide, farming and home construction have destroyed the richest valley-floor habitats, and roads have filled the floors of canyons and narrow valleys. In the arid region where I live, livestock graze along rare desert streams and around lakes and marshes.

Preserving critical habitats is not a new idea. Conservation organizations have programs that identify and urge protection of important habitats. The National Audubon Society, for instance, has initiated the Climate Strongholds program that focuses on the needs of individual species. The program has strong citizen-scientist opportunities for participation. Read about it here.

Most wildlife species will be lost over the next few decades and centuries, but it will be possible to prevent some of the losses through preservation of critical habitats. As changing weather patterns force governments to respond to the climate emergency, nature conservation advocates must work hard to explain the critical role nature plays in human survival and to convince governments to protect the best wildlife habitats.

Half for Nature

Current climate projections suggest that global carrying capacity will drastically decline over the next few centuries. Human civilization as we know and imagine it now will not survive. Once the Earth’s energy budget stabilizes, people can begin to rebuild cities and networks and evolution can begin to rebuild natural plant and animal diversity. It no longer seems logical to advocate Half for Nature. There will be no half that could sustain the natural communities and diversity we have now. “Half” was never a practical goal anyway. In this blog post, I’ve advocated for the “Best” for nature. I hope that is a practical goal. There could be masses of people jammed into cool mountain canyons, but it could be trees and animals instead.

Asking for More: Additional Carbon Cuts Please

GR: Moving from theoretical to practical, an article in Nature reports on the use of observed global warming to choose the best models for predicting future global warming. Future warming is normally estimated by combining several models. In the new research, the scientists found that the best models actually predict a warmer future than the combined models did. National commitments to reduce emissions have to increase.

Governments are curbing emissions, but not fast enough for 2C goal (Pic: Flickr/kris krug)

“Greater future global warming inferred from Earth’s recent energy budget”

Abstract:  “Climate models provide the principal means of projecting global warming over the remainder of the twenty-first century but modelled estimates of warming vary by a factor of approximately two even under the same radiative forcing scenarios. Across-model relationships between currently observable attributes of the climate system and the simulated magnitude of future warming have the potential to inform projections. Here we show that robust across-model relationships exist between the global spatial patterns of several fundamental attributes of Earth’s top-of-atmosphere energy budget and the magnitude of projected global warming. When we constrain the model projections with observations, we obtain greater means and narrower ranges of future global warming across the major radiative forcing scenarios, in general. In particular, we find that the observationally informed warming projection for the end of the twenty-first century for the steepest radiative forcing scenario is about 15 per cent warmer (+0.5 degrees Celsius) with a reduction of about a third in the two-standard-deviation spread (−1.2 degrees Celsius) relative to the raw model projections reported by the Intergovernmental Panel on Climate Change. Our results suggest that achieving any given global temperature stabilization target will require steeper greenhouse gas emissions reductions than previously calculated.” –Brown and Caldeira.

15,000 Scientists From 184 Countries Warn Humanity of Environmental Catastrophe

GR: This is the 25-year update of the warning scientists gave in 1992.

“More than 15,000 scientists have signed a chilling article titled “World Scientists’ Warning to Humanity: A Second Notice,” urging global leaders to save the planet from environmental catastrophe.

“The plea, published Monday in the international journal BioScience, is likely the largest-ever formal support by scientists for a journal article with 15,372 total signatories, Motherboard noted. The scientists represent 184 countries and have a range of scientific backgrounds. Prominent signatories include Jane Goodall, E.O. Wilson and James Hansen.

“The “Second Notice”—an update to the original version published 25 years ago by the Union of Concerned Scientists and signed by 1,700 scientists then—underscores the lack of progress from the original document.

“The first notice started with this statement: “Human beings and the natural world are on a collision course.” It described trends such as the growing hole in the ozone layer, pollution and depletion of freshwater sources, overfishingdeforestation, plummeting wildlife populations, as well as unsustainable rises in greenhouse gas emissions, global temperatures and human population levels.

“Unfortunately, the authors of the current article said that humanity has failed to progress on most of the measures.

“They ominously warned, “time is running out.”

“Especially troubling is the current trajectory of potentially catastrophic climate change” from the burning of fossil fuels and other human activities, the paper stated.

“William J. Ripple, lead author of the current article and a distinguished professor of ecology at Oregon State University, told the Associated Press he was stunned by the level of support for the manuscript.

“I initially sent it out to 40 of my colleagues,” he explained. “After 24 hours there were 600 scientists who signed it. Within two days, there were 1,200. There were so many people signing that our website crashed a couple of times.”

“According to the AP, the researchers document a number of alarming trends from 1992 to 2016, such as a 28.9 percent reduction of vertebrate wildlife, a 62.1 percent increase in CO2 emissions, a 167.6 percent rise in global average annual temperature change and a 35.5 percent increase in the global population (about 2 billion people).” –Lorraine Chow (More: https://www.ecowatch.com/scientists-environmental-warning-2509347840.html.)