Bacteria may contribute more to climate change as planet heats up

Bacteria may contribute more to climate change as planet heats up

SOURCE: Imperial College London DATE: November 12, 2019 SNIP: As bacteria adapt to hotter temperatures, they speed up their respiration rate and release more carbon, potentially accelerating climate change. By releasing more carbon as global temperatures rise, bacteria and related organisms called archaea could increase climate warming at a faster rate than current models suggest. The new research, published today in Nature Communications by scientists from Imperial College London, could help inform more accurate models of future climate warming. Bacteria and archaea, collectively known as prokaryotes, are present on every continent and make up around half of global biomass – the total weight of all organisms on Earth. Most prokaryotes perform respiration that uses energy and releases carbon dioxide – just like we do when we breathe out. The amount of carbon dioxide released during a given time period depends on the prokaryote’s respiration rate, which can change in response to temperature. However, the exact relationship between temperature, respiration rate and carbon output has been uncertain. Now, by bringing together a database of respiration rate changes according to temperature from 482 prokaryotes, researchers have found the majority will increase their carbon output in response to higher temperatures to a greater degree than previously thought. Lead researcher Dr Samraat Pawar, from the Department of Life Sciences at Imperial, said: “Rising temperatures therefore cause a ‘double whammy’ effect on many prokaryote communities, allowing them to function more efficiently in both the short and long term, and creating an even larger contribution to global carbon and resulting temperatures.” Lead author of the new research, PhD student Thomas Smith from the Department of...
Domino-effect of climate events could move Earth into a ‘hothouse’ state

Domino-effect of climate events could move Earth into a ‘hothouse’ state

SOURCE: The Guardian DATE: August 7, 2018 SNIP: A domino-like cascade of melting ice, warming seas, shifting currents and dying forests could tilt the Earth into a “hothouse” state beyond which human efforts to reduce emissions will be increasingly futile, a group of leading climate scientists has warned. This grim prospect is sketched out in a journal paper that considers the combined consequences of 10 climate change processes, including the release of methane trapped in Siberian permafrost and the impact of melting ice in Greenland on the Antarctic. The authors of the essay, published in Proceedings of the National Academy of Sciences, stress their analysis is not conclusive, but warn the Paris commitment to keep warming at 2C above pre-industrial levels may not be enough to “park” the planet’s climate at a stable temperature. “I do hope we are wrong, but as scientists we have a responsibility to explore whether this is real,” said Johan Rockström, executive director of the Stockholm Resilience Centre. “We need to know now. It’s so urgent. This is one of the most existential questions in science.” Rockström and his co-authors are among the world’s leading authorities on positive feedback loops, by which warming temperatures release new sources of greenhouse gases or destroy the Earth’s ability to absorb carbon or reflect heat. Their new paper asks whether the planet’s temperature can stabilise at 2C or whether it will gravitate towards a more extreme state. The authors attempt to assess whether warming can be halted or whether it will tip towards a “hothouse” world that is 4C warmer than pre-industrial times and far less supportive of...

Alive and Well: Microbes Add to Melting of Greenland Ice Sheet

SOURCE: Yale Climate Connections DATE: March 22, 2017 SNIP: Scientists are investigating a new “positive feedback” in Greenland’s melting ice sheet—as climate warms, more microbial growth on the ice sheet is darkening ice, and hastening ice melt and sea level...
More dire data, less climate change concern?

More dire data, less climate change concern?

SOURCE: Deutsche Welle DATE: Dec 10, 2016 SNIP: With Trump poised to dismantle US climate action, is this a sign of public burnout on the climate topic? Although European voters have indicated they see climate change as a more important factor in their voting than Americans, a similar trend is present: less importance attached to the climate change issue in the face of more short-term fears – such as terrorism, immigration and perhaps imminent geopolitical conflict. But even as climate change recedes from the spotlight, recent evidence shows that the situation is perhaps even more dire than originally thought: Two alarming new studies released over the past month have scientists worried. This week, the Colorado-based National Snow and Ice Data Center revealed that both the Arctic and Antarctic experienced record lows in sea ice extent in November – astonishing scientists who say it is unprecedented for sea ice to retreat at a time when the Arctic enters the coldest, darkest part of the year. The news has policymakers worried as well. “This news from the Arctic might be the start of a tipping point that we must avoid, because this would mean that we as human beings are losing control,” said Gerben-Jan Gerbrandy, a Dutch Liberal member of the European Parliament, at an event this week. … Last week, the Yale School of Forestry and Environmental Studies revealed alarming new research showing that the long-theorized “feedback loop” of climate change and soil carbon loss is indeed a real phenomenon – meaning that the rate of global temperature could rise much faster than expected. Thomas Crowther, who conducted the research,...