James Hansen: the story on HearLore

Venusian Atmosphere Research

In the late 1960s and early 1970s Hansen focused his research efforts on the atmosphere surrounding Venus. Scientists struggled to explain why the planet's surface remained so hot despite its distance from the sun. Hansen proposed that aerosols trapped internal energy within the thick carbon dioxide atmosphere. He examined the near-infrared reflectivity of ice clouds and compared them to actual observations of Venus. His radiative transfer models helped establish an upper limit for the size of ice particles if those clouds were made of water ice. By 1974 researchers still debated the composition of Venusian clouds with theories ranging from liquid water to ferrous chloride solutions. Hansen and Hovenier used sunlight polarization data to prove the clouds were spherical droplets of sulfuric acid. Kiyoshi Kawabata and Hansen expanded this work by analyzing variations in polarization across the planet. The Pioneer Venus project launched in May 1978 provided critical data that confirmed the presence of a thin haze layer above sulfuric acid clouds. Linear polarization measurements showed cloud drops had a radius of approximately one micrometer while submicrometre haze floated above the main layer.

When was James Hansen born and where did he grow up?

James Edward Hansen was born on the 29th of March 1941 in Denison, Iowa. He grew up as the son of James Ivan Hansen and Gladys Ray Hansen.

What scientific discoveries did James Hansen make about Venus during the late 1960s and early 1970s?

James Hansen proposed that aerosols trapped internal energy within the thick carbon dioxide atmosphere surrounding Venus. His work with Hovenier proved the clouds were spherical droplets of sulfuric acid using sunlight polarization data.

Why is James Hansen's Senate testimony on June 23rd 1988 considered a turning point for climate policy?

James Hansen testified before the United States Senate Committee on Energy and Natural Resources stating global warming had reached a level where cause and effect could be ascribed to the greenhouse effect. This hearing marked a pivotal moment when scientific discussion moved into full-blown policy debate and increased public awareness significantly.

How many times was James Hansen arrested for political activism between 2009 and 2013?

James Hansen was arrested multiple times including an arrest on the 23rd of June 2009 in Raleigh County West Virginia and another arrest on the 13th of February 2013 alongside Daryl Hannah and Robert F. Kennedy Jr. A two-week protest in August and September 2011 resulted in over twelve hundred arrests at the White House involving him.

What nuclear power arguments did James Hansen make starting in 2008 regarding climate change mitigation?

James Hansen advocated for nuclear power as a necessary tool to replace fossil fuels and mitigate carbon emissions. He co-authored a paper estimating that 1.8 million air pollution-caused deaths were prevented worldwide between 1971 and 2009 through nuclear use instead of fossil fuels.

James Hansen.

Venusian Atmosphere Research

The 1988 Congressional Testimony

Climate Model Development

Activism And Arrests

Nuclear Energy Advocacy

Honors And Legacy

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