Climate Letter #1545

A fascinating story about smoldering peatland fires (Horizon magazine).  Scientists are just beginning to get a handle on their dimensions and how they operate.  This was written by a professor who is involved in relevant research.  “When we have tried to put together an estimate of the carbon emissions the figures are staggering. We’re talking about the equivalent of between 10 to 15% of anthropogenic carbon emissions. This is more than all the vehicles in the world. This is more than the whole of the European Union…..There is a positive feedback loop between smouldering peat fires and climate change. If there is an excess of carbon emissions in the atmosphere, that leads to drier and hotter soil. Then based on our research, the probability of ignition and the fire size will increase. It’s a self-accelerating mechanism.”

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A new study describes the way climate change threatens future rice production (Stanford University).  “Rice is the largest global staple crop, consumed by more than half the world’s population—but new experiments from Stanford University suggest that with climate change, production in major rice-growing regions with endemic soil arsenic will undergo a dramatic decline and jeopardize critical food supplies…..rice yields could drop about 40 percent by 2100…..What’s more, changes to soil processes due to increased temperatures will cause rice to contain twice as much toxic arsenic than the rice consumed today.”  The experiments were based on a temperature increase of 5C, which the researchers hope will be avoided if societies are forewarned and act accordingly.

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Researchers explain the predicament faced by people who inhabit major river deltas (The Conversation).  The two lead authors of a new study wrote this article for the general public, about what happens when deltas are deprived of new supplies of sediment normally supplied by flowing rivers.  “The world’s river deltas take up less than 0.5 percent of the global land area, but they are home to hundreds of millions of people…..But many of the world’s deltas are now facing an existential crisis. Sea levels are rising as a result of climate change, while deltas are themselves sinking, and together this means the relative sea level is rising extra fast.”  The sinking can be alleviated, but that will require a number of difficult decisions and tradeoffs to be made.

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The power of algae blooms to accelerate the melting of glaciers is said to be underestimated (Reuters).  According to scientists who were interviewed, soot from forest fires that has landed on glaciers cause them to darken; then algae that can feed on carbon in the soot will grow and cause further darkening.  “These are not currently considered in our models for glacier melt and almost certainly will accelerate it further than our estimates currently show.”  Various research papers are underway covering the accelerating effect linked to algae blooms.

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