Daily Mail: NASA says droughts are becoming more frequent and severe

Drought-stricken areas now take longer to bounce back to normal as extreme dry conditions become more common

  • As global temperatures rise, droughts will become more severe this century 
  • In some areas, not recovering fully from droughts will become the new norm 
  • Drought recovery takes longer in the tropics and northern high latitude regions
  • This could lead to trees dying and increased emissions of greenhouse gases

As global temperatures continue to rise due to climate change, droughts are expected to become more frequent and severe in many regions during this century.

A new study co-led by NASA found that ecosystems took progressively longer to recover from droughts in the 20th century.

In some areas, not recovering fully from droughts will become the new norm, possibly leading to trees dying and increased emissions of greenhouse gases.

Global patterns of drought recovery time, in months. The longest recovery times are shown in shades of blue and pink, with the shortest recovery times in yellow. White areas indicate water, barren lands, or regions that did not experience a drought during the study period

The study, published August 10 in the journal Nature, was led by Dr Christopher Schwalm of Woods Hole Research Center in Massachusetts, and a researcher based at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California.

The study measured recovery time following droughts in different regions of the world.

To do this, researchers used projections from climate models based on observations made by NASA’s Terra satellite, as well as ground observations.

The researchers found that drought recovery was taking longer in all land areas.

However, there are two regions that are particularly vulnerable and where recovery took longer: The tropics and northern high latitudes.

HOW THEY DID THE STUDY

A study, published August 10 in the journal Nature, measured recovery time following droughts in different regions of the world.

To do this, researchers used projections from climate models based on observations made by NASA’s Terra satellite, as well as ground observations.

Specifically, the satellite observations were made by Terra’s Moderate Resolution Imaging Spectroradiometer (MODIS) instrument.

A study published in the journal Nature, measured recovery time following droughts in different regions of the world. To do this, researchers used projections from climate models based on observations made by NASA’s Terra satellite (pictured, rendering)

‘Data from our “eyes” in space allow us to verify our simulations of past and current climate, which, in turn, helps us reduce uncertainties in projections of future climate.’

The researchers say that recovery time is a crucial measurement for assessing the resilience of ecosystems, as it shapes the odds of crossing a tipping point after which trees begin to die.

Shorter times between droughts, in combination with longer drought recovery times, could lead to widespread tree death, making land areas less able to absorb carbon dioxides from the atmosphere.

The study comes amidst new research that there could be an increase in the number of heatwaves on Earth, with a bout of ‘super-heatwaves’ reaching 55°C (121°F) predicted to hit several areas if global temperatures rise by just 4°C (39°F).

The team found that the combination of heat and humidity, and the resulting heatwaves, will leave more people exposed to significant health risks, especially in East Asia and the US east coast.

In their paper, published in Scientific Reports, the researchers, led by Dr Simone Russo, said: ‘Humid-heat waves with these conditions were never exceeded in the present climate, but are expected to occur every other year at 4°C (39°F) global warming.’

http://www.dailymail.co.uk/sciencetech/article-4792908/Study-finds-droughts-frequent-severe.html