Environment: Can wildfires affect climate?

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A new U.S. Forest Service research paper outlines how wildfires can affect climate. Photo courtesy NOAA.

Smoke particles can cool ground temperatures and suppress cloud formation

By Summit Voice

SUMMIT COUNTY — Along with resulting in huge on-the-ground disturbance, wildfires also have an impact in the atmosphere. With wildfires expected to increase in a warming world, U.S. Forest Service researchers recently set out to document what some of those effects might be with a synthesis of recent research, focusing on the effect of emissions from wildfires on long-term atmospheric conditions.

“While research has historically focused on fire-weather interactions, there is increasing attention paid to fire-climate interactions,” said Yongqiang Liu, lead author and team leader with the SRS Center for Forest Disturbance Science. “Weather, the day-to-day state of the atmosphere in a region, influences individual fires within a fire season. In contrast, when we talk about fire climate, we’re looking at the statistics of weather over a certain period. Fire climate sets atmospheric conditions for fire activity in longer time frames and larger geographic scales,” Liu said.

Key findings included:

  • The radiative forcing of smoke particles can generate significant regional climate effects, leading to lower temperatures at the ground surface.
  • Smoke particles mostly suppress cloud formation and precipitation. Fire events could lead to more droughts.
  • Black carbon, essentially the fine particles of carbon that color smoke, plays different roles in affecting climate. In the middle and lower atmosphere, its presence could lead to a more stable atmosphere. Black carbon plays a special role in the snow-climate feedback loop, accelerating snow melting. Continue reading

Study confirms heating effects of greenhouse gas buildup

Doubling of CO2 likely to result in 2.2 to 4.8 degrees Celsius warming

New research helps pinpoint the amount of heating caused by greenhouse gases.

By Summit Voice

SUMMIT COUNTY — Climate scientists know that greenhouse gases like carbon dioxide and methane trap heat in the atmosphere, but there’s still some uncertainty about how the overall system responds to varying levels of those gases.

By studying the paleoclimatic record, researchers have been able to measure relationships between past greenhouse gas increases and temperatures to some degree, and new research is helping them evaluate past climate sensitivity data to help improve comparison with estimates of long-term climate projections developed by the Intergovernmental Panel on Climate Change.

The scientists found that the likely range of climate sensitivity consistently has been of the order of 2.2 to 4.8 degrees Celsius per doubling of CO2, which closely agrees with the IPCC estimates. Continue reading

Climate: Greenhouse gases hit new record high in 2011

Greenhouse gas concentrations are increasing.

Increased concentrations add up to 30 percent more heating effect in just the past 20 years

By Summit Voice

FRISCO — With heat-trapping greenhouse gases rising to a new record high in 2011, the World Meteorological Organization calculated that there has been a 30 percent increase in radiative forcing  – the warming effect on our climate – just in the past 20 years.

In its annual greenhouse gas bulletin, the WMO estimated that humankind has released about 375 billion tons of carbon the atmosphere as CO2 since the start of the industrial era in 1750. About half of this carbon dioxide remains in the atmosphere, with the rest being absorbed by the oceans and terrestrial biosphere. Continue reading

Global warming: ‘Half a billion atom bombs per year’

Extra atmospheric energy likely to manifest in intensification of global water cycle

*Editor’s note: Under a content-sharing agreement, Summit Voice will occasionally be offering stories from Climate Progress.

By Stephen Lacey

How much extra energy are we putting in the atmosphere through emission of greenhouse gases? One Australian researcher put it into context: “The radiative forcing of the CO2 we have already put in the atmosphere in the last century is … the equivalent in energy terms to almost half a billion Hiroshima bombs each year.”

With more energy radiating down on the planet rather than back up into space, the planet continues to heat up. As the atmosphere warms, it is able to hold more water vapor — thus strengthening the global hydrological cycle.

With all that extra energy, more water is pulled out of the subtropic regions and moved toward higher-precipitation areas in the subpolar regions, resulting in stronger droughts and stronger storms. Or, as the video above explains, how the wet gets wetter and the dry gets drier.

Visit Climate Progress for more.

 

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