Climate Letter #1222

Explanations given for the northern hemisphere heatwave and its possible duration (New Scientist).  The explanation comes from Jennifer Francis, whose expertise is widely accepted.  The duration forecast of weeks or even months is from several national meteorological offices.

–Here is a post that makes comparisons between the current heatwave and those of the past, with several videos.  I was especially interested in the two graphs that compare the global temperature anomaly of 2018 with that of 1976, showing how effects that were once concentrated have broadened with today’s heatwave superimposed on an underlying basic temperature increase of 0.7C over those four decades.  (The base used for both anomalies was the 1951-1980 average.)

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A new study focuses on the potential losses of biodiversity in the tropics.  This has great relevance to the idea of a “sixth extinction” because because more than three quarters of all relevant species live in that region, which is under many kinds of stress.  All of the important stress factors are discussed, among them climate change, which has the distinctive role of exacerbating most of the others.  The authors do not believe we are doing everything we could to forestall an impending collapse.

–No open access, but the paper’s abstract and identity of 170 reference studies can be found at this link:

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Another new study describes the effect of tropical deforestation and forest degradation on the atmospheric CO2 level.  Instead of acting as a net sink for some of human emissions these forests could become a net emitter.  This is not a new idea but tends to confirm what some previous research groups have been saying.  From the lead author, “Predicting how tropical forests will affect climate is a complex challenge—we do not know how climate will affect forests, nor if countries will meet their commitments to safeguard them. Worryingly, research indicates that forests could soon stop counteracting warming, and instead become a major source of greenhouse gas.”

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In many places environmental activism is a dangerous way of life.  Statistics are kept on how many are murdered each year because they get in the way of various profit-making interests, both legal and illegal.  Last year set a new record of 207 around the world.  Mongabay has the full story, including the number of killings by country for the year.  Brazil had the most, which is not surprising, followed by the Philippines.  “As alarming as the numbers Global Witness has reported are, the group says that they are only “the tip of the iceberg,” as limited data on killings means that several more likely went unrecorded.”

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