Extreme summer temperatures are already occurring more frequently in the United States, and will become normal by mid-century if the world continues on a business as usual schedule of emitting greenhouse gases, says a study led by Phil Duffy of the Lawrence Livermore National Laboratory. It showed that previously rare high summertime (June, July and August) temperatures are already occurring more frequently in some regions of the 48 contiguous United States.
'The observed increase in the frequency of previously rare summertime-average temperatures is more consistent with the consequences of increasing greenhouse gas concentrations than with the effects of natural climate variability, said Duffy. 'It is extremely unlikely that the observed increase has happened through chance alone.'
The team also modelled the period 2035-2064.
'What was historically a one in 20-year occurrence will occur with at least a 70 percent chance every year,' said Duffy 'This work shows an example of how climate change can affect weather extremes, as well as averages.'
Full report on ScienceDaily
'The observed increase in the frequency of previously rare summertime-average temperatures is more consistent with the consequences of increasing greenhouse gas concentrations than with the effects of natural climate variability, said Duffy. 'It is extremely unlikely that the observed increase has happened through chance alone.'
The team also modelled the period 2035-2064.
'What was historically a one in 20-year occurrence will occur with at least a 70 percent chance every year,' said Duffy 'This work shows an example of how climate change can affect weather extremes, as well as averages.'
Full report on ScienceDaily
