2019 Science Headline News
1-22-19 Satellites saw rapid Greenland ice loss
Greenland has gone through an "unprecedented" period of ice loss within the last two decades. The Grace satellites revealed a four-fold increase in mass being lost from Greenland's ice sheet from 2003-2013. The study in Proceedings of the National Academy of Sciences shows that ice loss subsequently stalled for 12-18 months. The research reveals how different areas of Greenland might contribute to sea-level rise in future. Scientists concerned about sea levels have long focused on Greenland's south-east and north-west regions, where glaciers continually force large chunks of ice into the Atlantic Ocean. But the largest sustained acceleration in ice loss from early 2003 to mid-2013 occurred in south-west Greenland, which is largely devoid of these large glaciers. "Whatever this was, it couldn't be explained by glaciers, because there aren't many there," said the study's lead author Michael Bevis, from The Ohio State University. "It had to be the surface mass - the ice was melting inland from the coastline." The ice melt accelerations in this region tracked a weather phenomenon known as the North Atlantic Oscillation (NAO). When in a particular ("negative") phase, the NAO enhances summertime warming and the solar radiation that reaches the Earth's surface, while reducing snowfall - especially in western Greenland. The researchers believe the melting in south-west Greenland is a combination of climate change and conditions brought on by the NAO. "These oscillations have been happening forever... so why only now are they causing this massive melt? It's because the atmosphere is, at its baseline, warmer. The transient warming driven by the North Atlantic Oscillation was riding on top of more sustained global warming," said Prof Bevis.
1-9-19 Report: US 2018 CO2 emissions saw biggest spike in years
A new report has found that US carbon dioxide emissions rose by 3.4% in 2018 after three years of decline. The spike is the largest in eight years, according to Rhodium Group, an independent economic research firm. The data shows the US is unlikely to meet its pledge to reduce emissions by 2025 under the Paris climate agreement. Under President Donald Trump, the US is set to leave the Paris accord in 2020 while his administration has ended many existing environmental protections. While the Rhodium report notes these figures - pulled from US Energy Information Administration data and other sources - are estimates, The Global Carbon Project, another research group, also reported a similar increase in US emissions for 2018. The US is the world's second largest emitter of greenhouse gases. And last year's spike comes despite a decline in coal-fired power plants; a record number were retired last year, according to the report. The researchers note that 2019 will probably not repeat such an increase, but the findings underscore the country's challenges in reducing greenhouse gas output. In the 2015 climate accord, then President Barack Obama committed to reducing US emissions to at least 26% under 2005 levels by 2025. Now, that means the US will need to drop "energy-related carbon missions by 2.6% on average over the next seven years" - and possibly even faster - to meet that goal. "That's more than twice the pace the US achieved between 2005 and 2017 and significantly faster than any seven-year average in US history," the report states. "It is certainly feasible, but will likely require a fairly significant change in policy in the very near future and/or extremely favourable market and technological conditions. "
11-22-18 Climate crisis as greenhouse gas levels reach record highs
Greenhouse gas levels have reached new record highs, prompting experts to warn that without rapid cuts climate change will have increasingly destructive and irreversible impacts. Average concentrations of carbon dioxide hit new highs of 405.5 parts per million (ppm) in 2017, up from 403.3 ppm in 2016 and 400.1 ppm in 2015, levels not seen for millions of years. Levels of other key greenhouse gases methane and nitrous oxide in the atmosphere also rose, says the UN’s World Meteorological Organisation (WMO). There is no sign of a reversal in the trend in increasing greenhouse gas levels, which is driving climate change, sea level rises and more extreme weather and making oceans more acidic, the UN experts warned. In its annual bulletin on greenhouse gas levels, the WMO also warned of a resurgence in a potent greenhouse gas and ozone-depleting substance known as CFC-11, which has been linked to illegal refrigerator factories in China. “The science is clear. Without rapid cuts in carbon dioxide and other greenhouse gases, climate change will have increasingly destructive and irreversible impacts on life on Earth,” said WMO secretary-general Petteri Taalas. “The last time the Earth experienced a comparable concentration of carbon dioxide was 3-5 million years ago, when the temperature was 2-3°C warmer and sea level was 10-20 metres higher than now,” said Taalas. The new IPCC special report on global warming of 1.5°C shows that deep and rapid reductions of emissions of carbon dioxide and other greenhouse gases will be needed in all sectors of society and the economy,” said IPCC chairman Hoesung Lee.
2019 Science Headline News