Sea level rise could hit 1.3m by the end of the century unless measures are taken to end coal power by 2050, a new study says. The research combines the new estimates of Antarctica’s contribution to sea level rise with the latest emissions projection scenarios. The 1.3m projection is if no efforts are taken to curb global carbon emissions, with almost half a metre of this coming from melting land ice in Antarctica. However, the extra contribution from Antarctica would not kick in if warming was kept at less than 1.9C above pre-industrial levels. “The 1.5C limit in the Paris Agreement is a much safer bet to avoid this additional contribution than only achieving 2C,” lead author Alexander Nauels told the Guardian. The study supports evidence that global warming of 2C or more could push parts of the West Antarctic Ice Sheet past a melting threshold that would rapidly increase the pace of sea level rise, says InsideClimate News. The study is the third in recent days that suggests sea level rises could be larger, and happen more rapidly, than previously thought, says the Washington Post.

Companies from the technology and oil and gas industries have stepped into the debate over the future of the US electricity system, raising objections to the Trump administration’s plans to support coal-fired and nuclear power plants. Microsoft, Walmart, ExxonMobil, General Electric and Apple are among the companies that argued — either directly or through industry groups — against news proposals from US energy secretary Rick Perry to make payments to power plants that have 90 days of fuel on site. The policy would likely only include coal, nuclear and some hydro stations. The consultation has prompted more than 680 comments, with opponents saying the regulations would damage competition in electricity markets, raise prices for consumers and stifle investment in cleaner forms of generation, and supporters arguing a new framework is needed to keep available generation capacity that might be needed in a crisis. Meanwhile, Reuters reports that the US has signed a deal with Denmark to expand cooperation on offshore wind power. Danish companies DONG Energy and Vestas say the Trump administration is increasingly looking at Europe’s experience as it seeks to kick-start the sector. And finally, the Environmental Protection Agency (EPA) is to review how laws like the Clean Air Act and Clean Water Act affect energy industry job losses, says another Reuters piece. The measure was one of four initiatives proposed by the EPA to help carry out an executive order issued by President Donald Trump in March. He directed cabinet chiefs to identify ways to ease regulatory burdens on energy development. The EPA will conduct a study to weigh how its regulations affect job losses in sectors like coal. A federal court has ruled that the EPA did not need to conduct such an assessment.

Environmental Protection Agency chief Scott Pruitt’s plan for a “red-team, blue-team exercise” to debate concerns on climate change is taking shape as the Huffington Post obtains a list of prominent climate sceptics that the Heartland Institute, a right-wing thinktank, assembled and submitted to the agency in May. “The list includes Edwin Berry, the self-funded researcher who compares belief in climate change to Aztec human sacrifices; Alan Carlin, the so-called “whistleblower” who challenged the EPA’s finding that rising greenhouse gases warm the planet; and, for good measure, Joe Bastardi, Fox News’ favorite yelling meteorologist,” says the HuffPost. The names included on the list suggest that “the Heartland Institute wants the debate to go directly after the scientific and legal underpinnings of the EPA’s regulations on climate change.” This means, rather than debating the regulatory approaches, “they want to undermine the conclusion that climate change is a real problem,” the article says. The DeSmogBlog also has the story.

Despite Brazil’s worst recession in history, national greenhouse gases emissions have risen 8.9% in 2016, new estimates show, reaching the highest level since 2004. Emissions from land-use change grew 23% in 2016, accounting for roughly half of all greenhouse gases released into the atmosphere by Brazil. This was driven by a 29% increase in Amazon deforestation during the period between August 2015 and July 2016. The recession has led to a decrease in emissions from most other economic activities, the data shows, with the largest drop – a 7.3% fall – coming from the energy sector.

The Mail Online and the Independent both have rather breathless coverage of a new study in Nature Communications about reconstructing 100m-year old records of ocean temperatures. The study suggests that existing methods to measure oxygen isotopes in fossilised tiny marine creatures give estimates of ocean temperatures in the late Cretaceous and Paleogene periods that are too high. Ocean temperatures at that time were actually “significantly lower than is generally accepted,” the paper says. The Indy says this “major mistake” in the “methodology widely used to understand sea temperatures” means modern climate change is “far worse than we had previously calculated”. The Indian Express says the “corrected temperature calculations could worsen impact of climate change”. However, as NASA’s Dr Gavin Schmidt pointed out on Twitter, the study “says nothing about modern instrumental records, nor model simulations of change. So can’t possibly affect future expectations [of climate change].”

Representatives of two thinktanks respond to the Dieter Helm report in the papers today. First, Diego Zuluaga, head of financial services and tech policy at the right-wing thinktank the Institute of Economic Affairs, writes in the Telegraph that the report “gives a scathing account of the state of the UK energy market”. Despite bringing in measures to “discourage consumption” of energy, “we are artificially raising energy use by exempting bills from the standard rate of VAT and by giving direct subsidies to pensioners,” Zuluaga argues. “It is possible to have cheaper energy and a clean environment. We don’t have to accept lower living standards to meet our climate goals.,” he writes. The Helm report “argues for simplification, decentralisation and market-based solutions”, and Zuluaga agrees: “This implies a single price for all carbon emissions, rather than the existing Byzantine system whereby some industries are exempt from carbon pricing but pay in other ways, whilst others pay twice and yet others are entirely exempt. CO2 is CO2, whether it comes from a car, an aeroplane or a cement factory.” In the Times, John Constable, energy editor of the climate sceptic lobby group Global Warming Policy Forum, writes that the Helm report “has torn away the fig leaves covering the government’s nakedness”. “Policy interventions, he [Helm] tells us, are so numerous and badly designed that they have resulted in costs well in excess of what is needed to meet emissions targets,” says Constable. The recommendations in the report are “sweeping and brilliant”, says Constable: “The present policies are counterproductive and erode public support for measures to address climate change. They must be replaced by firm capacity auctions, so renewables pay for their own intermittency, and by a single carbon price to find the cheapest technologies.”

“The recent fires in Northern California were not the result of a perfect storm of unlucky factors or unforeseen conditions,” argues Dr Gregory Simon, assistant professor geography and environmental studies at the University of Colorado, in The Conversation. On the contrary, “we could see these fires and their disastrous outcomes coming decades in advance. It was only a matter of time.” “And yet, despite fully comprehending these immense fire risks, cities have continued to plan and extend human settlements further into already fire-prone areas,” he writes. In addition, many decades of intentional fire suppression policies have enabled fuel build-up across the Western US. “We need to recognise the role society’s ravenous appetite to develop historically high-risk areas plays,” Simon argues. “Only then can we start to reverse calamitous urban planning trends.”

The Medieval Climate Anomaly (MCA) is a well-recognized climate change in many parts of the world around 1000-1200 AD. A new study presents a palaeotemperature analysis for the MCA in Africa and Arabia, based on data from 44 locations. The vast majority of Afro-Arabian onshore sites suggest a warm MCA, with the exception of the southern Levant where the MCA appears to have been cold. MCA cooling has also been documented in some areas due to changes in the wind systems leading to an intensification of cold water upwelling. Offshore cores from outside upwelling systems mostly show warm MCA conditions. The most likely key drivers of the observed medieval climate change are solar forcing and ocean cycles. Conspicuous cold spikes during the earliest and latest MCA may help to discriminate between solar (Oort Minimum) and ocean cycle (Atlantic Multidecadal Oscillation) influence. Compared to its large share of nearly one quarter of the world’s land mass, data from Africa and Arabia are still significantly underrepresented in global temperature reconstructions of the past 2000 years.

An extreme El Niño event can be identified by its unusually high rainfall over the eastern equatorial Pacific Ocean exceeding a threshold of 5 mm per day. This identification is supported by upward atmospheric velocity in the region. Using these definitions and statistical analysis, a new paper shows that the projected increase in frequency of extreme El Niño in response to greenhouse warming is not merely a consequence of increasing trends in the mean rainfall. Rather, it is due to increased probability of atmospheric deep convection made conducive by the faster warming of the eastern equatorial Pacific Ocean than the surrounding regions.

Marine ice-cliff instability (MICI) could accelerate the retreat of the Antarctic Ice Sheet if ice shelves that buttress it are lost. The present-day grounding zones of the Pine Island and Thwaites glaciers in West Antarctica need to retreat only short distances before the retreat becomes unstable and accelerates. It is thought that MICI is triggered when this retreat produces ice cliffs above the water line with heights approaching about 90 metres. However, observational evidence confirming the action of MICI has not previously been reported. A new study presents observational evidence that rapid deglacial ice-sheet retreat into Pine Island Bay proceeded in a similar manner to that simulated in a recent modelling study, driven by MICI. They infer rapid and sustained ice-sheet retreat driven by MICI, commencing around 12,300 years ago and terminating before about 11,200 years ago, which produced large numbers of icebergs. Their findings demonstrate the effective operation of MICI in the past, and highlight its potential contribution to accelerated future retreat of the Antarctic Ice Sheet.