Washington: Global warming likely contributed to heat waves last year in Asia, Europe and Australia, but not all extreme weather events worldwide could be linked to climate change, international scientists said on Monday.
A total of 16 extreme events -- including rain, flood, droughts and storms -- were analyzed in an annual report called, "Explaining Extreme Events of 2013 from a Climate Perspective," published by the Bulletin of the American Meteorological Society.
The peer-reviewed report is compiled by 92 scientists from around the globe.
"Japan, Korea and China all experienced extremely hot summers in 2013. Studies of these events concluded that human-caused climate change made these heat waves more likely," said the National Oceanic and Atmospheric Administration. Three of four lead scientists on the report are from NOAA.
There was also evidence to support the notion that human-caused climate change has increased the likelihood of heavy, once-in-100-year rains that India experienced in June 2013, said the report.
The burning of fossils fuels, which spew carbon dioxide and contribute to mounting levels of greenhouse gases, was also found to play "a substantial part in Western Europe's 2013 hot and dry summer," NOAA said.
When it came to record hot temperatures in Australia last year, "five independent studies all pointed toward human influence having a substantial increase in the likelihood and severity" of those heat waves.
In New Zealand, "human-caused climate change caused meteorological conditions that were more favorable for drought in 2013," said the report.
With multiple teams of scientists scrutinizing various weather events, not every extreme event was found to be influences by climate change. In some cases, natural variability in climate was deemed the leading factor.
Regarding California's drought -- the worst in the state's history -- three teams of US researchers found that human factors did not influence the lack of rainfall last year.
"One team found evidence that atmospheric pressure patterns increased due to human causes, but the influence on the California drought remains uncertain," said NOAA.