Climate tipping points — too risky to bet against

Climate tipping points — too risky to bet against

SOURCE: Nature DATE: November 27, 2019 SNIP: Politicians, economists and even some natural scientists have tended to assume that tipping points1 in the Earth system — such as the loss of the Amazon rainforest or the West Antarctic ice sheet — are of low probability and little understood. Yet evidence is mounting that these events could be more likely than was thought, have high impacts and are interconnected across different biophysical systems, potentially committing the world to long-term irreversible changes. Here we summarize evidence on the threat of exceeding tipping points, identify knowledge gaps and suggest how these should be plugged. We explore the effects of such large-scale changes, how quickly they might unfold and whether we still have any control over them. The Intergovernmental Panel on Climate Change (IPCC) introduced the idea of tipping points two decades ago. At that time, these ‘large-scale discontinuities’ in the climate system were considered likely only if global warming exceeded 5 °C above pre-industrial levels. Information summarized in the two most recent IPCC Special Reports (published in 2018 and in September this year) suggests that tipping points could be exceeded even between 1 and 2 °C of warming. If current national pledges to reduce greenhouse-gas emissions are implemented — and that’s a big ‘if’ — they are likely to result in at least 3 °C of global warming. This is despite the goal of the 2015 Paris agreement to limit warming to well below 2 °C. Some economists, assuming that climate tipping points are of very low probability (even if they would be catastrophic), have suggested that 3 °C warming is optimal from a cost–benefit perspective. However,...
Pointless emails: they’re not just irritating – they have a massive carbon footprint

Pointless emails: they’re not just irritating – they have a massive carbon footprint

SOURCE: The Guardian DATE: November 26, 2019 SNIP: Stop! Don’t send that email. Don’t offer thanks or send a jokey message. If you do, you will add to your carbon footprint. Be rude, say nothing – and save the planet. A new study commissioned by energy company OVO reckons Brits send more than 64m unnecessary emails every day, and that if every adult in the UK sent one fewer “thank you” email a day we would save more than 16,433 tonnes of carbon a year – equivalent to 81,152 flights to Madrid or taking 3,334 diesel cars off the road. How can one little email destroy the planet, I ask Mike Berners-Lee, a professor in the environment centre at Lancaster University, and brother of Tim Berners-Lee, inventor of the web, who advised OVO on the research. “When you are typing, your computer is using electricity,” he says. “When you press send it goes through the network, and it takes electricity to run the network. And it’s going to end up being stored on the cloud somewhere, and those data centres use a lot of electricity. We don’t think about it because we can’t see the smoke coming out of our computers, but the carbon footprint of IT is huge and growing.” The electricity I grasp; the cloud is a bit beyond me. “It’s made up of enormous data centres all over the world,” Berners-Lee explains. “They are burning through huge amounts of electricity.” Super-efficient communication and storage is killing us. Every silver lining has a cloud. Berners-Lee admits the numbers are “crude estimates”, but says they are a useful...
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...
Global Pollution Is Rising Again and Won’t Peak Before 2040

Global Pollution Is Rising Again and Won’t Peak Before 2040

SOURCE: Bloomberg DATE: November 12, 2019 SNIP: Global greenhouse-gas pollution rose for a second year, ending a lull in emissions and putting the world on track for further increases through 2040 unless governments take radical action. The findings in the International Energy Agency’s annual report on energy paint a grim outlook for efforts to rein in climate change and mark a setback for the increasingly vocal environmental movement. It said emissions levels would have to start falling almost immediately to bring the world into line with ambitions in the Paris Agreement to limit temperature increases to well below 2 degrees Celsius (3.6 degrees Fahrenheit) since the industrial revolution. Instead, the organization’s most likely scenario shows net emissions won’t reach zero until at least 2070, or 20 years past the deadline suggested by climate scientists. Strong economic growth, surging demand for electricity and slower efficiency gains all contributed to a 1.9% increase in carbon dioxide emissions from energy in 2018, the IEA said in a report released on Wednesday. It’s another indication that efforts to shift the world away from the most polluting fuels are moving too slowly to have a major impact on preserving the environment. Developing nations have deployed more coal plants even as industrial countries work to phase out the fuel, a legacy that will be felt for years to come since power plants are built to run for decades. Global coal demand rose for the second year in a row in 2018. Three quarters of that came in the Asia Pacific region. If global coal policies remain unchanged, then demand will keep expanding for two decades,...
Aviation climate targets may drive 3 million hectares of deforestation

Aviation climate targets may drive 3 million hectares of deforestation

SOURCE: Rainforest Foundation Norway DATE: October 1, 2019 SNIP: As the general assembly meeting of the International Civil Aviation Organization (ICAO) got underway in Montreal, Rainforest Foundation Norway’s new report ‘Destination deforestation‘ goes into the heated debate about “flight shame” and the role of the aviation sector in contributing to the climate crisis. The report reviews the status of the targets the aviation industry has set for alternative fuels and shows how high the risk is that expanding biofuel use in aviation will cause the last thing the world wants or needs right now: increased deforestation. The aviation industry has set an aspirational goal to reduce its CO2 emissions by 50 percent in 2050 (compared to 2005), without limiting growth. Central to this vision is a near complete shift from conventional jet fuel to alternative aviation fuels. Near total replacement of fossil fuel would be needed to meet this target. A number of technologies are available to produce aviation biofuels, or even to produce aviation fuels from electricity, but the only one of these technologies currently operating at a commercial scale is the ‘HEFA’ (Hydroprocessed esters and fatty acids) process to produce jet fuel from vegetable oils and animal fats. The cheapest and most readily available feedstocks for HEFA jet fuel are palm oil and soy oil, which are closely linked to tropical deforestation. Unless alternative aviation fuel policies actively support more sustainable options, it is likely that meeting the aviation industry’s aspirations to reduce emissions would lead to a sharp increase in demand for soy and palm oils. The report estimates that meeting the aspirational targets outlined by...