Global wildlife populations have fallen by 58% since 1970, a report says. The Living Planet assessment, produced by the Zoological Society of London (ZSL) and WWF every two years, suggests that if the trend continues that decline could reach two-thirds among vertebrates by 2020. The figures suggest that animals living in lakes, rivers and wetlands are suffering the biggest losses. Human activity, including habitat loss, wildlife trade, pollution and climate change contributed to the declines. Dr Mike Barrett, head of science and policy at WWF-UK, said: “It’s pretty clear under ‘business as usual’ we will see continued declines in these wildlife populations. But I think now we’ve reached a point where there isn’t really any excuse to let this carry on.” The previous report, published in September 2014, found that biodiversity dropped by 52% between 1970 and 2010. The story is covered widely around the world, including by the Telegraph, Express, Daily Mail, Guardian and Time magazine.

The Times reports on Carbon Brief’s analysis published earlier this week showing what proportion the aviation sector will likely consume of the UK’s carbon budget in 2050. The paper says: “Severe restrictions will have to be placed on carbon emissions from cars, home heating and industry if Britain is to meet its green targets while expanding aviation capacity. Jets could produce two-thirds of the carbon dioxide that Britain is allowed to emit by 2050, an analysis has found. Expansion of Heathrow and other airports will allow passenger numbers to rise to 480 million a year by 2050, double the current level, with flights producing up to 51 million tons of CO2. Britain can emit only 72 million tons of the gas in 2050 if it is to stick to the pledge it made in last year’s Paris agreement on climate change to try to limit global warming to 1.5C, according to the analysis by the Carbon Brief website.”

Climate change is threatening to force millions of people to become refugees and spark major wars that could “completely destabilise” the world, a leading general has warned. And countries which attempted to deal with the coming crisis by resorting to “narrow nationalistic instincts” – for example, by building walls to keep out refugees – will only make the problem worse, according to Major General Munir Muniruzzaman, chairman of the Global Military Advisory Council On Climate Change, which was set up in 2009 to investigate the security implications of climate change.

The New York State Supreme Court has ordered the oil giant and its accounting firm to produce documents subpoenaed in a highly charged investigation of whether the company concealed from investors and the public what it knew about climate change as long as four decades ago. The New York State Attorney General Eric Schneiderman, who issued a subpoena in August, sought to force PricewaterhouseCoopers to provide the documents after ExxonMobil said it would not permit PwC to provide certain documents based on a Texas statute that Exxon said provided “accountant-client privilege”. The New York Court ruled that Exxon’s interpretation of the Texas statute was “flawed,” and said the Texas statute does not preclude PwC from producing the documents requested by the New York attorney general’s office. The court also stated that New York law, rather than Texas law, governed the dispute. The Hill and Reuters also carry the story.

The costs of failing to act on climate change are even higher than they were a decade ago, according to the author of the influential Stern Review which marks its 10th anniversary this week. Lord Nicholas Stern told reporters: “Whatever you think of those models, and I cautioned about not being over literal, I think they gave a reliable story in terms of the costs of inaction would be very big, and whatever they were then I think they’re bigger now.” He added: “The science is more troubling, we’ve delayed, and concentrations [of greenhouse gases in the atmosphere] are a good deal higher than they were then.” The Guardian notes that Stern now feels that China leads the way on climate action, making the country both a competitor and inspiration for other nations: “You can make a strong case for that…You have radical change in energy and very big structural change in the economy, moving very strongly towards service sectors and high-tech.”

There is continuing coverage in the UK newspapers of the death of Gordon Hamilton, a 50-year-old Scottish climate scientist who was killed in Antarctica last weekend. Hamilton had been part of a US team of climate-change experts camped in an area known as the “Shear Zone”, where a moving ice shelf had created numerous fissures, when his snowmobile plunged into a crevasse. The Mirror, BBC News and Sky News are among the others carrying the news.

Buchanan, a physicist and science writer, is concerned about “how far we remain from getting carbon emissions under control – and how much wishful thinking is still required to believe we can do so”. He is specifically concerned that IPCC projections “rely heavily on the assumption that new technologies will allow humans to start sucking carbon out of the atmosphere on a grand scale, resulting in large net negative emissions sometime in the second half of this century. This might happen, but we don’t know how to do it yet.” He adds: “The assumptions about negative emissions amount to a bizarre step in what ought to be a cautious and conservative analysis. The IPCC scenarios essentially ignore the vast uncertainty surrounding a technology that does not yet exist, and about our ability to ramp it up to the required scale.”

Murray hits out at the so-called “lukewarmism” adopted by “Times columnist, coal baron, Conservative peer and former Northern Rock Chairman Viscount Matt Ridley”. Ridley portrays it as a “middle position”, but, in reality, says Murray, it “sits right at the very bottom end of the temperature projections for this century proposed by scientists through the IPCC and accepted by governments and most business leaders”. He adds: “From banking to Brexit, Ridley has a long track record of bringing his self-styled brand of ‘rational optimism’ to numerous questions regarding future risks and opportunities, but if lukewarmism’s projections prove overly optimistic then using them to justify rolling back measures to tackle climate change could be far and away his riskiest idea yet.”

The editorial is directed at Priti Patel, the new secretary of state for international development, someone who once said the department she now leads should be shut down: “If one of Britain’s proudest recent achievements is its leadership on development, Ms Patel stands on the verge of a massive act of national vandalism…The positive case for aid is not being made. Unmentioned go the obligations that Britain has to poorer countries, because of the damage it has caused through empire, climate change and pernicious supply chains. Perhaps hamstrung by the lobbying laws or the need to secure their own DfID funding, Oxfam, ActionAid and the like are mutely allowing the new minister and her supporters to trash the case for aid. How best to do development aid is always open to evaluation. That it needs doing should not be. The NGOs must get their act together, fast.”

A few recent case studies have suggested that certain crops could benefit from solar dimming geoengineering, but new research shows it is likely to have a detrimental impact on growing groundnut. Using a collection of crop-climate model simulations, the researchers show that groundnut yields in India decrease by up to 20% as a result of solar dimming geoengineering. However, there is some reassuring news, the researchers note, as: “crop yields return to the non-geoengineered values within a few years once the intervention is ceased.”

The observed intensification of heavy rainfall across many regions of the world confirms “both theory and model predictions made decades ago,” a new paper says. This is an example of how a “seemingly complex and potentially computationally intractable” process can be observed and recorded in a relatively simple way, the researchers note. As the world continues to warm in future, “there will be more opportunities to test climate predictions for other variables against observations,” the paper concludes.

A new paper looks at the “major science challenge” of understanding if, and how, rapid warming in the Arctic is affecting the weather of mid-latitude regions. “The chaotic nature of atmospheric circulation precludes easy answers,” the researchers say. Emphasising coordination for both scientific progress and communication to the public, the researchers lay out a “way forward” for the research community to further their understanding of the links between the Arctic and the mid-latitudes.