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Scientists have now identified another powerful negative-feedback mechanism which acts to reduce the effects of global warming. This is according to a new paper published in the journal Nature Geoscience, which states that rising temperatures cause plants to emit higher levels of aerosols, which cools the planet.
According to Pauli Paasonen of Helsinki University, who led the research, ‘Aerosol effects on climate are one of the main uncertainties in climate models. Understanding this mechanism could help us reduce those uncertainties and make the models better.’ Aerosols are suspended particles in the atmosphere which have various effects. Black carbon soot, for example, heats the planet by absorbing sunlight, but the majority of aerosols tend to cool things down. This is achieved through the presentation of nuclei, which clouds form on and reflect heat back into space.
Even firmly pro-warmist researchers agree that aerosols have powerful effects for environmental wellness, but there is less of a consensus as to how much aerosol can be expected in the atmosphere of the future, and current models aren’t thought to handle this factor at all well. The work by Paasonen and his colleagues’ implies that there is and will be a lot more aerosol in the air and cooling the planet than we thought.
Scientists have long suspected that a slightly warmer climate makes plants give off highly increased amounts of cooling aerosols, but Paasonen and his colleagues have now shown this to be the case. Their research shows that the feedback acts on continental scales, which overcomes earlier difficulties experts have had in accounting for the tricky effects of the boundary layer where the atmosphere interacts with the surface beneath.
Paasonen explained, ‘One of the reasons that this phenomenon was not discovered earlier was because these estimates for boundary layer height are very difficult to do. Only recently have the reanalysis estimates been improved to where they can be taken as representative of reality.’ Passonen noted that the plant feedback cannot wipe out global warming on its own, as it needs some warming before it appears. However, the results show that forecasts for global warming in the future should be adjusted downward by around a degree, which is a big deal in global-warming terms.