Two recent reports, released by NASA and the US National Climate Data Centre, have confirmed that last month was the warmest June since records began.
June was the fourth consecutive month that had broken temperature records, the US National Oceanic and Atmospheric Administration (NOAA) said. Global monthly records were also broken in March, April and May.
June was the 304th month in a row that recorded a global average temperature higher than the 20th century average. February 1985 was the last month temperatures fell below the average.
NOAA’s State of the Climate Global Analysis June 2010 report said the six months from January to June were the hottest on record. The three months April-June were the warmest on record for the northern hemisphere.
The report also quoted figures from the US National Snow and Ice Data Centre, which reported the lowest June Arctic sea ice extent since records began in 1979.
June’s Arctic sea ice extent was about 10.6% (or 1.29 million square kilometres) below the 1979–2000 average, the NOAA report said. It was the 19th consecutive June that recorded below-average Arctic sea ice extent.
New temperature records have also been set in several African and Asian countries during May and June, the July 10 Climate Progress blog said.
Kuwait, Saudi Arabia, Iraq, Chad, Niger, Pakistan, Sudan and Burma all had record highs. Pakistan’s record high, a sweltering 53.5°C on May 26, was Asia’s highest recorded temperature.
Scientists say the record high temperatures this year are powerful evidence of human-caused climate change.
Temperatures should actually be lower than normal because the Earth’s current orbit has placed it at its furthest point from the sun.
Despite this, a paper released in June by scientists from NASA Goddard Institute for Space Studies said recent high temperatures have “occur[ed] when the recent minimum of solar irradiance is having its maximum cooling effect”.
As the Earth orbit brings it closer towards the sun, even more warming is likely.
The paper concluded: “Human-made climate change has become an issue of surpassing importance to humanity.” It confirmed that “global warming on decadal time scales is continuing without letup”.