Rate of Change
Biosphere Climate Change Daily Earth Science Repost

Wired for survival, not climate change (Part 2)

Previously: The climate change conundrum – We desire a clean, livable environment, but we also want security. The tension between these two aspirations creates a quandary because we must sacrifice security today, so future generations enjoy an environmentally healthy tomorrow.

The cost of ignoring climate change

Geological history reminds us that the earth’s changing environments result from a combination of unique interactions between the atmosphere, hydrosphere, geosphere, and biosphere. Climate is, and always has been, a dynamic feature of these interactions. Put another way; the climate is continually changing. Why then should we worry about climate change?

Life has flourished on the earth in one form or another for over 3.5 billion years. But scientists estimate that 99.9 percent of all species throughout history are now extinct. Organisms, including Homo sapiens, don’t exist separate from the ecosystem they call home. Destroy or change the ecosystem, then the species living there must either adapt or perish.

Geoscientists recognize five mass extinction events throughout geological history. These extinction events occurred at the end of the Ordovician (445 million years), the end of the Devonian (359 million years), the end of the Permian (250 million years), the end of the Triassic (200 million years), and the end of the Cretaceous (65 million years). All mass extinctions had one thing in common: rapid climate change. Sometimes the earth was warming rapidly, and at other times it was cooling. But it was the rate of change, not change itself, that sent countless species into the void of extinction. Over 90 percent of the earth’s species disappeared in the late Permian “Great Dying” as temperatures soared, and the oceans became unlivable. 

Rate of Change

The earth has been warming and cooling for 4.5 billion years. But what makes modern, Anthropocene, climate history different is the rate of change. At the end of the last ice age, average global temperatures experienced a geologically rapid increase of 5°C in 6000 years (a rate of 0.8°C per 1000 years). However, over the past 50 years, the rate of temperature increase has been equivalent to 13°C per 1000 years. This rate of increase is unprecedented in geological history, except during mass extinctions.

Life is tenacious but not invincible.  Historically, species have disappeared at a rate of about 0.01 percent every 100 years. But almost five hundred species went extinct in the past decade. This rate is 50 times greater than the background level. Biological evolution needs many generations to work its magic.

The rate of change is all-important. All mass extinctions share a common theme: Climate change occurs faster than evolutionary change can keep up. Climate change and species extinction today, in the Anthropocene, are both occurring more quickly than at any period of the earth’s long history. The cost of ignoring climate change is high.

Solutions

The search for a path forward brings to mind an oil quote from Wallace E. Pratt, “Where oil is first found is in the minds of men.” Oil lurks far below the ground and geologists search through data to tease out hints of where it may reside. Then someone puts the various jig-saw pieces together and envisions the oil field long before its discovery by the drill bit. This quote also extends to complex problem solving in general. Viable solutions will arise from the vision and creativity of individuals as they grapple with climate change. Whether society implements those solutions is a different question. We also need to be realistic in our expectations.

Saying we will stop climate change by moving to net-zero emissions is disingenuous. Net-zero provides a target where carbon emitted into the atmosphere is balanced out by carbon taken up in various types of carbon sinks. When humanity achieves this goal, the global temperature will continue to rise due to climate lag and atmospheric aerosol reductions. Global temperatures will increase by up to 1°C during the 40 years after reaching global net-zero emissions. So, the current Paris Agreement target of holding warming to 2°C is actually closer to 3°C.

This observation is not to say that reductions in fossil fuel emissions aren’t necessary. These reductions are a vital part of any plan forward. The salient message is that a hotter planet is coming. The critical question is, what will humanity do to mitigate the geographical, environmental, and social dislocation that climate change will bring? Humans are very skilled at adaptation, and those skills must be part of building bridge to the future.    

(Next: Electricity, a pressure point for mitigating climate change)


ArcheanWeb:

Triassic trials and tribulations, a new beginning (Source: ArcheanWeb) – https://archeanweb.com/2020/07/16/triassic-trials-and-tribulations-a-new-beginning/ Also:

Mystery of the Late Devonian extinction (Source: ArcheanWeb) – https://archeanweb.com/2020/06/09/mystery-of-the-late-devonian-extinction/ Also:

Net-zero emissions – But no cooling down without Negative Emissions Technology (Source: ArcheanWeb) – https://archeanweb.com/2020/07/09/net-zero-emissions-but-no-cooling-down-without-negative-emissions-technology/ Also:


Sources:

Feature Image: Fish Kill Pollution (Modified) – By United States Fish and Wildlife Service. – Public Domain Images, United States Fish and Wildlife Service., Public Domain, https://commons.wikimedia.org/w/index.php?curid=24859656

William House
William is an earth scientist and writer with an interest in providing the science "backstory" for breaking environmental, earth science, and climate change news.