Feeds

Another negative climate feedback: Warmer plants cool the planet

Tree hugging really does fight global warming

The next step in data security

Another powerful negative-feedback mechanism which acts to reduce the effects of global warming has been identified, as scientists say that rising temperatures cause plants to emit higher levels of planet-cooling aerosols.

"Aerosol effects on climate are one of the main uncertainties in climate models," explains Pauli Paasonen of Helsinki uni. "Understanding this mechanism could help us reduce those uncertainties and make the models better."

Aerosols - suspended particles - in the atmosphere have various effects. Black carbon soot absorbs sunlight and heats the world up, but most other kinds of aerosol tend to cool things down, mostly by presenting nuclei for clouds to form on and so reflecting heat back into space. There is widespread scientific agreement, even among firmly pro-warmist researchers, that aerosols have powerful effects - but just how much aerosol can be expected in the atmosphere of the future is not at all well known, and current models aren't thought to handle this factor at all well.

Paasonen and his colleagues' new work indicates that there is and will be a lot more aerosol in the air and cooling the planet than had been thought, as they have carried out detailed measurements showing that a slightly warmer climate makes plants give off much increased amounts of cooling aerosols. This had long been suspected, but previous studies had been able to identify such an effect only in very specific and limited locations: Paasonen and his colleagues have now shown that the feedback acts on continental scales, overcoming earlier difficulties in accounting for the always tricky effects of the boundary layer where the atmosphere interacts with the surface beneath.

"One of the reasons that this phenomenon was not discovered earlier was because these estimates for boundary layer height are very difficult to do," explains Paasonen. "Only recently have the reanalysis estimates been improved to where they can be taken as representative of reality."

On its own, according to Paasonen, this newly quantified feedback would not wipe out global warming (logically enough, as it needs some warming before it appears). But he and his colleagues consider that it means forecasts should be adjusted downward by around a degree, which is a big deal in global-warming terms. Various other previously unknown cooling or negative-feedback effects have been identified in recent research - for instance, melting ice sheets are said to create a massive carbon sink and the mysterious "Criegee intermediates" are also thought to be a powerful planet coolant.

Such mechanisms may help to explain why global warming has been on hold for the past decade and more, and why some projections now suggest much lower levels of near-future warming than had been feared.

Paasonen and his colleagues' new paper is published in the journal Nature Geoscience. ®

New hybrid storage solutions

More from The Register

next story
PORTAL TO ELSEWHERE scried in small galaxy far, far away
Supermassive black hole dominates titchy star formation
Bacon-related medical breakthrough wins Ig Nobel prize
Is there ANYTHING cured pork can't do?
Boffins say they've got Lithium batteries the wrong way around
Surprises at the nano-scale mean our ideas about how they charge could be all wrong
Edge Research Lab to tackle chilly LOHAN's final test flight
Our US allies to probe potential Vulture 2 servo freeze
Europe prepares to INVADE comet: Rosetta landing site chosen
No word yet on whether backup site is labelled 'K'
Stray positrons caught on ISS hint at DARK MATTER source
Landlubber scope-gazers squint to horizons and see anti-electron count surge
Cracked it - Vulture 2 power podule fires servos for 4 HOURS
Pixhawk avionics juice issue sorted, onwards to Spaceport America
prev story

Whitepapers

Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.
WIN a very cool portable ZX Spectrum
Win a one-off portable Spectrum built by legendary hardware hacker Ben Heck
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Beginner's guide to SSL certificates
De-mystify the technology involved and give you the information you need to make the best decision when considering your online security options.