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The US space agency NASA has appealed to CSIRO to abandon plans to cut a key monitoring program that it says will undermine Australia and the world's ability to monitor and predict climate change.
Brent Holben, the project scientist in charge of NASA's Aerosol Robotic Network, urged CSIRO to reconsider any plans it had to cut or withdraw its contribution to the program, according to a letter obtained by Fairfax Media. 
"I understand that CSIRO is undertaking a major restructuring that may lead to the closure of AeroSpan [CSIRO's partner program]," Dr Holben wrote in the letter addressed to Alex Wonhas, a senior CSIRO executive, and dated   May 1, 2016.
"The purpose of this letter is to express my dismay about this, on behalf of NASA and the global aerosol community," he said.
Fairfax Media understands the AeroSpan program - which includes eight automated monitoring sites across Australia - is earmarked to be shut along with other micro-meteorology research done by CSIRO's Yarralumla staff in Canberra. (See CSIRO map below of the eight sites.)
Understanding aerosols - the distribution and character of airborne particles and clouds  - "represent the single greatest source of uncertainty in climate simulations", Dr Holben said.
CSIRO's contribution has largely been to help calibrate and validate satellite readings that cannot easily distinguish between different types of aerosols. These range from dust and industrial pollutants to sea salt. 
In return, Australia has been promised "unfettered access" to international data, such as from European Space Agency's Sentinel satellites.
NASA's letter notes Geoscience Australia has estimated Earth Observation services are worth $5.5 billion to the Australian economy annually, a windfall that will rise to $8.8 billion by 2030.
The cuts are part of 275 jobs to go from CSIRO, many of them in key climate or water roles. The AeroSpan cost to CSIRO is understood to be less than half a million dollars a year and involve just two researchers.
Chief executive Larry Marshall - whose three-year contract extension has been endorsed by the Turnbull government - has said that Australia's primary research agency must divert resources away from climate monitoring and modelling towards adaptation and mitigation.
The NASA letter said measurements of aerosols were "a fundamental component of climate predictions on both regional and global scales".
Climate monitoring has gained additional prominence this week, with the Cape Grim site in north-west Tasmania expected to report within days that baseline carbon-dioxide levels have exceeded 400 parts per million for the first time, as reported by Fairfax Media. CSIRO is also cutting staff at this site. 
International angst
Fairfax Media understands that NASA's complaint has been echoed by the European Space Agency, and individual national research organisations from Japan, Italy and Germany.
Some agencies have been warning their own staff for months to take into account the possible impacts of CSIRO's cuts.
"CSIRO has pledged to continue some of these critical measurements but the question arises as to how will quality be assured and will they be adaptable as scientific priorities evolve when the science teams that nurture them are dispersed," a senior US climate scientist from another US agency told Fairfax Media. "Field programs where there have been joint contributions of resources are particularly threatened."
Cutting the AeroSpan program would also harm the work to be done by the new Climate Science Centre CSIRO has recently set up, NASA said.
Steven Sherwood, one of the world's leading researchers into clouds and climate change at the University of NSW, said the CSIRO program cut was "idiotic".
"We don't even know if aerosols are increasing, decreasing or staying the same during the past 20 years," Professor Sherwood said. "If you stop observing now, you'll never know."
He said the biggest single variable in climate model projections was how they treated aerosols and their impact on the brightness of clouds - and therefore how much of the sun's radiatin are being reflected back to space. More and brighter clouds could mean global warming will be less rapid. 
'Blowing a hole'
Abandoning the AeroSpan project would end aerosol assessment over an entire continent - Australia - and remove "effective coverage of a much larger region of the Southern Hemisphere", NASA's Dr Holben said.
Fairfax Media sought comment from CSIRO. A spokesman for Science Minister Christopher Pyne said the government "has not been contacted by any of the organisations mentioned with concerns".
"This process has been as a result of decisions taken by the CSIRO made by the experts who run it in line with the organisations priorities and the Australian Government strongly supports the independence of the CSIRO to make its own decisions."
However, Kim Carr, Labor's shadow science minister, said it was "scandalous that the government is trying to wash their hands of their responsibilities". A Shorten government would immediately intervene to halt the cuts to key climate programs by CSIRO, he said.
"A future government will have to attend to the destruction that [these cuts] have caused," he said. "The cost to our international reputation is immense."
Adam Bandt, Greens Science spokesman, said: "Malcolm Turnbull is blowing a hole in humanity's knowledge of the world around us."
"Any cuts must be postponed until after the election, when a new power-sharing Parliament can restore funding to the CSIRO," Mr Bandt said.
Geoscience Australia, one of CSIRO's partners, said it was "aware that the CSIRO is considering changes to its Aerospan service".
"While the cessation of Aerospan would not immediately impact on the ability of Geoscience Australia to deliver our programs, it is an important part of Australia's Earth observation infrastructure and one the international community values," the spokesman said. "At this time there is no proposal in place for Geoscience Australia to take over the role."
Another partner, the Bureau of Meteorology, said "the full details of changes at the CSIRO and potential impacts on Bureau operations are not yet confirmed".