The planet has been building up temperatures at the rate of four Hiroshima bombs of heat every second, and it’s all our fault, say climate scientists.
Hurricane Katrina and superstorm Sandy are just two examples of how extreme weather will intensify, Australia’s Climate Action Summit has heard.
Humans are emitting more carbon dioxide into the atmosphere than any other time in history, says John Cook, Climate Communication Fellow from the Global Change Institute at the University of Queensland.
‘‘All these heat-trapping greenhouse gases in our atmosphere mean … our planet has been building up heat at the rate of about four Hiroshima bombs every second - consider that going continuously for several decades.’’
In a speech on extreme weather in Sydney on Saturday, Mr Cook said about 90 per cent of global warming was going into the oceans, which act like a natural thermometer along with changes in land, ice, and animal species.
Distributions of trees are shifting towards cooler areas such as the poles or mountains, and animal species are responding to global warming by mating earlier in the year.
‘‘This isn’t because animals are getting randier, it’s because the seasons themselves are shifting,’’ Mr Cook said.
120 climate records were broken in Australia this January, including the hottest month and the hottest day.
New colours had to be added to temperature maps to denote highs of over 50 and 54 degrees celsius.
Warmer air holds more water, so Australia will experience heavier rainfall in wetter areas, while dry regions are becoming drier.
There will be more category four and five tropical cyclones, and a ‘‘catastrophic’’ rating has already been added to fire gauges.
Mr Cook said studies have tried to put a number on how much of global warming is caused by humans, ‘‘and the rough answer is, all of it’’.He said for the past two decades, 97 per cent of scientists have been in agreement human activity is causing warmer temperatures.
But he said this is not filtering down to the public, who think scientists are about 50/50 on the issue.
