Climate-change is happening, say scientists

The research was contained in a new report, headed by the US National Oceans and Atmospheric Administration (NOAA), which features input from over 300 scientists from 160 research groups in 48 countries.

The report confirms that the past decade was the warmest on record and that the Earth has been growing warmer over the last 50 years.

The research is based on new evidence which was not contained in the UN’s Intergovernmental Panel on Climate Change report of 2007, which has been attacked by climate-change sceptics.

The NOAA-led research found that 10 measurable planet-wide features used to gauge global temperature changes are consistent with a warming world.

Seven indicators are rising: air temperature over land, sea-surface temperature, air temperature over oceans, sea level, ocean heat, humidity and tropospheric temperature in the ‘active-weather’ layer of the atmosphere closest to the Earth’s surface. Just three indicators are declining: Arctic sea ice, glaciers and spring snow cover in the Northern hemisphere.

The Earth is warming
“For the first time, and in a single compelling comparison, the analysis brings together multiple observational records from the top of the atmosphere to the depths of the ocean,” said Jane Lubchenco PhD, under-secretary of commerce for oceans and atmosphere and NOAA administrator.

“The records come from many institutions worldwide. They use data collected from diverse sources, including satellites, weather balloons, weather stations, ships, buoys and field surveys. These independently produced lines of evidence all point to the same conclusion: our planet is warming,” she added.

The report emphasises that human society has developed for thousands of years under one climatic state, and now a new set of climatic conditions are taking shape. These conditions are consistently warmer, and some areas are likely to see more extreme events like severe drought, torrential rain and violent storms.

Taking the long-term view on climate change
“Despite the variability caused by short-term changes, the analysis conducted for this report illustrates why we are so confident the world is warming,” said Peter Stott, PhD, contributor to the report and head of Climate Monitoring and Attribution of the United Kingdom Met Office Hadley Centre.

“When we look at air temperature and other indicators of climate, we see highs and lows in the data from year to year because of natural variability. Understanding climate change requires looking at the longer-term record. When we follow decade-to-decade trends using multiple data sets and independent analyses from around the world, we see clear and unmistakable signs of a warming world,” he explained.

While year-to-year changes in temperature often reflect natural climatic variations such as El Niño-like events, changes in average temperature from decade-to-decade reveal long-term trends such as global warming.

The NOAA-led research showed that each of the past three decades has been much warmer than the decade before. At the time, the 1980s was the hottest decade on record. In the 1990s, every year was warmer than the average of the previous decade. The 2000s were warmer still.

“The temperature increase of one degree Fahrenheit over the past 50 years may seem small, but it has already altered our planet,” said Deke Arndt, co-editor of the report and chief of the Climate Monitoring Branch of NOAA’s National Climatic Data Centre. “Glaciers and sea ice are melting, heavy rainfall is intensifying and heat waves are more common. And, as the new report tells us, there is now evidence that over 90pc of warming over the past 50 years has gone into our ocean.”

Read the US National Oceans and Atmospheric Administration-led report on climate change.