The true magnitude of global warming is hidden, scientists warn: ScienceAlert
Increasingly strong wind have been increasingly sweeping dust from Earth’s deserts into our skies since the mid-1800s. New data suggests this uptick may have masked up to 8 percent of current global warming.
Using satellite data and ground measurements, researchers have discovered a steady increase in these microscopic airborne particles since 1850. Soil dust in ice cores, ocean sediments and peat bogs shows that the level of mineral dust in the atmosphere has increased by about 55 percent over that time.
By scattering sunlight back into space and disturbing high-altitude clouds that can act as a blanket trap warmer air underneaththese dust particles have an overall cooling effect, essentially masking the true magnitude of the current extra heat energy vibrating around our atmosphere.
Atmospheric physicist Jasper Kok of the University of California, Los Angeles, explains that this amount of dust would have reduced warming by about 0.1 degrees Fahrenheit. Without the dust, our current warming so far would be 2.3 degrees Fahrenheit (1.2 degrees Celsius).
“We show that desert dust has increased and probably counteracted some greenhouse warming, which is lacking in current climate models,” say Cook. “The increased dust hasn’t caused much cooling — the climate models are still close — but our findings imply that greenhouse gases could only be causing even more global warming than models currently predict.”
higher wind speeds, drier soilsand changes in human land use they all affect the amount of dust that enters our atmosphere. Some of this then falls into our oceans, feeding important nutrients such as iron to photosynthesizing plankton that absorb carbon as they grow and reproduce.
This complicated desert dust cycle has yet to be factored into our climate models, and it is still unclear whether the amount of desert air particles will increase or decrease in the future.
“Adding the increase in desert dust, which accounts for more than half the mass of particles in the atmosphere, allows us to increase the accuracy of climate model predictions,” say Cook. “This is extremely important because better forecasts can make better decisions about how to reduce or adjust climate change.”
This research was published in Nature Reviews Earth and Environment.
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