By Dr Benny Peiser
If global temperatures continue to rise, Antarctica’s melting glaciers will cause the oceans to rise, as well as drastic changes in climate. However, new research by British Antarctic Survey shows that Antarctica paradoxically saw a 10 percent increase in snowfall over the last 200 years.
The increase in snowfall doesn’t contradict previous estimates of ice loss around Antarctica’s coast, but it does make the picture more complicated. Previous climate change models, proposed in 2013, predicted that global sea levels would rise by a meter by the year 2100 due in part to melting Antarctic ice, but those estimates have proven to be flawed. —Outer Place, 9 April 2018
A new consistent reconstruction of the solar activity of the last 9000 years offers a more reliable estimate of the long-term evolution of the solar variability. —Chi Ju Wu et al. (2018) Astronomy & Astrophysics 5 April 2018
Following four years of trials, which saw thousands of wheat varieties tested in the unforgiving sub-Saharan heat, scientists have successfully turned what was first thought of as a “crazy idea” into a vital new food crop. With more than 1 million smallholders living along the Senegal River basin, which also runs through Mali and Mauritania, it was an important strategic area to trial the wheat. The strain of wheat can withstand constant 40C [104 degrees Fahrenheit] temperatures and has been developed by the International Centre for Research in the Dry Areas (Icarda). —Mark Hillsdon, The Guardian, 23 March 2018
The Global Warming Policy Foundation (GWPF) has criticised Ofcom for its ruling against a BBC interview with Lord Lawson. In his interview with the BBC’s Today Programme on 10 August 2017, Lord Lawson pointed out that while some extreme events had increased, others had diminished.
Overall, however, extreme weather events had not increased according to the IPCC. Without providing any evidence to justify disputing the IPCC’s conclusions, Ofcom claimed that Lawson’s statement about the extreme weather was incorrect and not sufficiently challenged by the BBC presenter during the interview.
Ofcom, however, appears to base its ruling on information from unnamed complainants, the BBC (and possibly from other unnamed sources) without publishing that information or where it obtained it from. As a result, nobody is able to see it and judge its credibility. It did not ask Lord Lawson for any information regarding his statements. That Ofcom should judge on scientific matters without justifying their decision sets a worrying precedent concerning the oversight of journalists. —Global Warming Policy Foundation, 10 April 2018
Scientists in the Earth System Science Center (ESSC) at The University of Alabama in Huntsville (UAH) have calculated how much false warming NOAA-14 reported so the false warming could be removed from a long-term global atmospheric temperature record collected by MSU’s on satellites since mid-November 1978. —University of Alabama, Huntsville, 6 April 2018
Read more at climatechangedispatch.com
Big Increase In Antarctic Snowfall
By Jonathan Amos
Scientists have compiled a record of snowfall in Antarctica going back 200 years. The study shows there has been a significant increase in precipitation over the period, up 10%.
The effect of the extra snow locked up in Antarctica is to slightly slow a general trend in global sea-level rise. However, this mitigation is still swamped by the contribution to the height of the oceans from ice melt around the continent.Some 272 billion tonnes more snow were being dumped on the White Continent annually in the decade 2001-2010 compared with 1801-1810. This yearly extra is equivalent to twice the water volume found today in the Dead Sea.
Put another way, it is the amount of water you would need to cover New Zealand to a depth of 1m.
Dr Liz Thomas presented the results of the study at the European Geosciences Union (EGU) General Assembly here in Vienna, Austria.
Image copyright SPL. Image caption Much of the extra snow has fallen on the Antarctic Peninsula
“There’s been a lot of focus on the recent era with satellites and how much mass we’ve been losing from big glaciers such as Pine Island and Thwaites. But, actually, we don’t have a very good understanding of how the snowfall has been changing.
“The general assumption up until now is that it hasn’t really changed at all – that it’s just stayed stable. Well, this study shows that’s not the case.”
Copyright BAS. Image caption Cores have been collected across the continent – making this the largest study of its kind
Dr Thomas and colleagues examined 79 ice cores drilled from across Antarctica. These long cylinders of frozen material are essentially just years of compacted snow.
By analysing the cores’ chemistry, it is possible to determine not only when their snows fell but also how much precipitation came down. For example, one key marker used to differentiate one year from the next, even seasons, is hydrogen peroxide.
This is a photochemical product that forms in the atmosphere when water vapour encounters sunlight.
“For us, that’s perfect. Antarctica works like an on-off switch with the long ‘polar nights’ in winter and long periods of daylight in summer,” Dr Thomas explained.
The previous, most extensive survey of this kind assessed just 16 cores. The new study is therefore much more representative of snowfall behaviour across the entire continent.
It found the greater precipitation delivered additional mass to the Antarctic ice sheet at a rate of 7 billion tonnes per decade between 1800 and 2010 and by 14 billion tonnes per decade when only the period from 1900 is considered.
Most of this extra snow has fallen on the Antarctic Peninsula, which saw significant increases in temperature during the 20th Century.
“Theory predicts that, as Antarctica warms, the atmosphere should hold more moisture and that this should lead therefore to more snowfall. And what we’re showing in this study is that this has already been happening,” Dr Thomas said.
Image copyright ESA. Image caption Artwork: Satellites routinely map Antarctica, but their data record is only about 25 years
The BAS researcher is keen to stress that the increases in snowfall do not contradict the observations of glacial retreat and thinning observed by satellites over the last 25 years. Although the extra snow since 1900 has worked to lower global sea level by about 0.04mm per decade, this is more than being countered by the ice lost to the oceans at Antarctica’s margins, where warm water is melting the undersides of glaciers.
Dr Anna Hogg, from Leeds University, UK, uses radar satellites to measure the shape and mass of the ice sheet.
She told BBC News: “Even with these large snowfall events, Antarctica is still losing ice mass at a faster rate than it is gaining mass from snowfall, mainly due to the regions of known ice dynamic instability, such as in the Amundsen Sea Embayment which includes Pine Island and Thwaites glaciers.
“The Antarctic 4.3mm contribution to global sea level since about 1992 is still our best estimate.”
Liz Thomas’ research has been published in the EGU journal Climate of the Past
Read more at www.bbc.co.uk