Researchers see a human impact on wind, rain
Photo taken by Daragh McGrath
In this century, scientists have discovered how profoundly we humans are linked – or “coupled” – to nature.
And now, researchers see a mechanism for human–made pollution to be slowing down winds and reducing rainfall in some places. This study was led by Mark Jacobson at Stanford University. He looked at aerosols: microscopic particles from vehicles and power plants that form a city’s haze.
Jacobson used satellite data to link aerosols over land with wind speed. He explained to Earth & Sky that a heated land surface causes air to rise. It then mixes with cooler and faster air above. But aerosols act like a heat shield.
Mark Jacobson: So, it turns out that when you add aerosols to the air, aerosols as a whole, they tend to cool the ground. And as a result, they should reduce the mixing of the fast winds from above the surface to the surface.
Jacobson told Earth & Sky that slower winds mean less evaporation of water to form clouds, and less rainfall.
Mark Jacobson: We looked primarily in California at the effect on water supply. What we found was that the aerosol pollution, from humans, was reducing the water supply by about two to five percent.
He said the yearly loss of water is enough to fill two–thirds of a new reservoir from a dam planned for California’s San Joaquin River. Our thanks to NASA: explore, discover, understand.
Our thanks to:
Mark Z. Jacobson
Associate Professor
Dept. of Civil & Environmental Engineering
Stanford University
This is amazing! We’re affecting the WIND and the RAIN? When are people going to WAKE UP about this stuff?
Dear Ruby,
What do you think it will take for a wonderfully adaptive, efficient and intelligent species like Homo sapiens to end the denial of what is present everywhere before our eyes?
It is not my intention to be smart alecky about the pressing global challenges we are observing and trying to discuss, but one of two things is likely happening. Either what Dr. Jacobsen, you and I are seeing is somehow inadequately communicated by us or what many too many people believe is potentially disasterous and insulting to human intelligence.
Either human beings are or we are not having an impact on the natural world and, regardless of what people believe to be true, whatsoever is is, is it not?
Thanks always,
Steve
and it’s hard to say “so what” when it’s decreasing our water supply in CA.
Dear Lesterette,
As important as it is for individuals to gain an adequate awareness of how we, human beings, perniciously impact the Earth, its resource base and frangible ecosystem services, it is just as vital that nation-states and business conglomerations accept their responsibilities for acknowledging the potential global challenges posed to humanity by certain overgrowth activities of the human species now overspreading the Earth. Personal awareness and the acknowledgement of government/corporate responsibility by leaders of the world’s political economy could set the stage for addressing and overcoming whatever threats are presented to humanity by the human population.
Always,
Steve