Africa’s iconic baobab trees – which can live for 2,000 years or more – have started to die out in mysterious circumstances, a new study suggests. Of the 13 oldest known baobabs in the world, four have died in the last two decades, the research shows, and another five are close to collapse. BBC News reports that the researchers behind the new study suspect the demise may be linked to climate change, but have no direct evidence to prove this. “We suspect that the demise of monumental baobabs may be associated at least in part with significant modifications of climate conditions that affect southern Africa in particular,” said the team. “However, further research is necessary to support or refute this supposition.” The Washington Post reports that, in Zimbabwe, baobab deaths are reportedly being accompanied by some type of fungus that turns the trees black before they die. However, the new study concludes that the deaths “were not caused by an epidemic.” The Times, Mail Online and New Scientist also have the story.

A group of billionaires including Bill Gates, Jeff Bezos, Jack Ma, Mukesh Ambani, and Richard Branson are to invest in two start-ups developing energy storage technologies, according to Quartz. In 2016, the group launched Breakthrough Energy Ventures (BEV) with the intention of investing at least $1bn in radical new energy technologies to fight climate change. Quartz reports today that Form Energy, a US start-up working on battery storage, and Quidnet Energy, which uses water to store energy, will be the first to receive investment.

The world’s supply of vegetables could be severely diminished by 2050 unless urgent action is taken to tackle climate change, new research finds. The research suggests that global average yields of common crops such as soy beans and lentils are set to decrease as a result of increased temperatures and water shortages. This could, in turn, have a knock-on effect on public health, warn researchers from the London School of Hygiene and Tropical Medicine. “Our study shows that environmental changes such as increased temperature and water scarcity may pose a real threat to global agricultural production, with likely further impacts on food security and population health,” said lead author Dr Pauline Scheelbeek. Press Association also have the story.

Australia’s current greenhouse gas emissions reductions targets for 2030 are not compatible with its commitments under the Paris Agreement, according to new research. A paper from the progressive thinktank the Australia Institute finds the government’s target of a 26-28% reduction on 2005 levels is “inadequate according to any recognised principle-based approach” and the Labor target of a 45% reduction is “the bare minimum necessary for Australia to be considered to be making an equitable contribution to the achievement of the Paris agreement’s two degree target”.

The revival of supersonic aircraft could upend global efforts to cut emissions from the aviation industry, writes Carl Pope, former executive director of the Sierra Club, an environmental organisation in the US, in the New York Times. In recent years, a number of start-ups in the US and beyond have been competing to relaunch supersonic air travel for the luxury market. However, Pope points out that the Concorde, a super-fast plane which took its inaugural flight in 1976, burnt through around two tonnes of fuel just taxiing and four times as much fuel per passenger as a Boeing 747 jumbo jet. “New supersonic aircraft will help devour that carbon budget faster than ever,” Pope writes. “These aircraft will also pollute our skies and, with their sonic booms, break the calm we all need.”

“Tracking all the relevant publications on climate change has become impossible,” writes Jan Minx, professor of climate change and public policy at the Priestley International Centre for Climate at the University of Leeds, in the Guardian. The authors of the Intergovernmental Panel on Climate Change (IPCC) sixth assessment report “have a massive task on their hands” sorting through the relevant literature, she says. “Even if there was no further growth over the next three years, the relevant literature to be reviewed for the IPCC’s sixth assessment will be somewhere between 270,000 and 330,000 publications. This is larger than the entire climate change literature before 2014.” Tackling the issue will require “systematic research synthesis” and “machine learning techniques”, Minx writes.

“The Wall Street Journal (WSJ) Opinion page has long had a conservative skew, and unfortunately that has extended to politicising climate change with biased and factually inaccurate editorials,” scientist Dana Nuccitelli writes in the Guardian. Nuccitelli points to a series of opinion pieces written by climate sceptics and published in the newspaper over the past few weeks, including an opinion questioning “the well-established facts that sea level rise is accelerating,” Nuccitelli writes.

A changing climate could be behind the deaths of some of Africa’s oldest and largest baobab trees, a new “brief communication” paper suggests. Analysing more than 60 of the largest and potentially oldest baobab trees in Africa, the researchers found that eight of the 13 oldest and five of the six largest baobabs have either completely died or had their oldest parts collapse since 2005. While the exact cause of this “unprecedented event” is still unclear, the researchers “suspect that the demise of monumental baobabs may be associated at least in part” with climate change.

Increasing levels of CO2 in the atmosphere will have a “significant direct impact on Northern Hemisphere summer temperature, heat stress, and tropical precipitation extremes”, a new study suggests. The research focuses on the “direct” impacts of rising CO2 levels – defined as “all the effects of CO2 on climate beside those occurring through ocean warming, but including feedbacks over land”. These direct impacts highlight “the need to explicitly limit atmospheric CO2 concentration when formulating allowable emissions”, the researchers conclude.