Each year’s average temperature is determined by a number of factors, including solar activity and the status of the El Niño/La Niña phenomenon. But heat-trapping gases that have accumulated in the atmosphere, largely from the burning of fossil fuels, have become a dominant force, pushing the Earth’s climate out of its normal range. The planet is now close to 0.8 degrees Celsius warmer than it was a century ago. Hidden within annual averages and expected variability are startling instances of new temperature and rainfall records in many parts of the world — weather extremes that would once be considered anomalies but that now risk becoming the new norm as the Earth heats up.

Worldwide, 2011 was the second wettest year on record over land. (The record was set in 2010, which also tied 2005 as the warmest overall.) Heavier deluges are expected on a warmer planet; each temperature rise of 1 degree Celsius increases the amount of moisture the atmosphere can hold by about 7 percent. Higher temperatures also can fuel stronger storms.

Brazil started the year with the deadliest natural disaster in its history: in January, a month’s worth of rain fell in a single day in Rio de Janeiro state, leading to floods and landslides that killed at least 900 people. That same month, flooding in eastern Australia covered an area nearly the size of France and Germany combined. Overall, it was the third wettest year in Australia since recordkeeping began in 1900.

The most expensive weather disaster of 2011 was the flooding in Thailand in the second half of the year, which ultimately submerged one third of the country’s provinces. At $45 billion worth of damage — equal to 14 percent of Thailand’s gross domestic product — it was also the costliest natural catastrophe the country ever experienced.

In October, more than 100 people died as two storms — one from the Pacific and the other from the Caribbean — pounded Central America with rain. In western El Salvador, nearly 1.5 meters of rain (almost 5 feet) fell over 10 days. And in December, Tropical Storm Washi hit the Philippines, creating flash floods that killed more than 1,200 people.

The 2011 Atlantic hurricane season had 19 named storms. Hurricane Irene brought extreme flooding to the northeastern United States in August, with total damages topping $7.3 billion. The year was the wettest on the books for seven states in the country, while it was among the driest for several others. Although the extremes appear to balance out, making for a near-average year, in fact a record 58 percent of the contiguous United States was either extremely wet or extremely dry in 2011.

Indeed, as is expected on a hotter planet, while some parts of the globe were overwhelmed by rain in 2011, others were distinguished by dryness. A severe drought in the Horn of Africa that began in 2010 devolved into a crisis situation in 2011, characterized by crop failure, exorbitant food prices, and widespread malnutrition. Exacerbated by chronic political instability and a belated humanitarian response, the death toll may have exceeded 50,000 people.

Back in North America, a drought that began in late 2010 and worsened over 2011 led hundreds of farmers from northern Mexico to march to that nation’s capital in January 2012 to draw the government’s attention to their suffering. Nearly 900,000 hectares of farmland (some 2.2 million acres) and 1.7 million head of livestock were lost due to the dryness — the worst in Mexico’s 70+ years of data collecting.

Scorching heat, drought, and wildfires across the U.S. Southern Plains and Southwest caused farm, ranch, and forestry damages that exceeded $10 billion in 2011. Wichita Falls, Texas, experienced 100 days over 100 degrees Fahrenheit — far more than the previous record of 79 days set in 1980. Oklahoma and Texas had the hottest summers of any states in history, breaking by a wide margin the record set in 1934 during the Dust Bowl. James Hansen, director of NASA’s Goddard Institute for Space Studies, writes that the likelihood of such extreme heat waves “was negligible prior to the recent rapid global warming.” Texas also had its lowest rainfall on record. Invigorated by the heat and drought, wildfires burned across an estimated 1.5 million hectares (3.7 million acres) in the state.

For the continental United States, summer 2011 was the second warmest in history. Nearly three times more weather stations hit record highs than lows in 2011, in line with a trend of increasing heat extremes. Whereas in the middle of the 20th century there were close to the same number of record highs and lows — as would be expected absent a strong warming trend — in the 1990s highs began outpacing lows. In the first decade of this century, there were twice as many record highs as record lows.

Worldwide, seven countries set all-time temperature highs in 2011: Armenia, China, Iran, Iraq, Kuwait, Republic of the Congo, and Zambia. Interestingly, Zambia also was the only country to experience an all-time low temperature when it dropped to -9 degrees Celsius (16 degrees Fahrenheit) in June. Kuwait experienced the year’s highest temperature, with thermometers measuring a searing 53.3 degrees Celsius (127.9 degrees Fahrenheit), the highest temperature ever recorded on Earth during the month of August. Even more threatening to health than daytime highs are extra hot nighttime minimum temperatures, which do not allow any respite from the heat. The world’s hottest 24-hour minimum ever — 41.7 degrees Celsius (107 degrees Fahrenheit) — was recorded in Oman in June 2011.

Even the Arctic had a notably warm year, with the 2011 temperature a record 2.2 degrees Celsius (4 degrees Fahrenheit) above the mean for 1951–80. Barrow, Alaska, the northernmost U.S. city, spent a record-breaking 86 consecutive days at or above freezing, far more than the previous record of 68 days set in 2009.

In fact, over the last 50 years temperatures in the Arctic have risen more than twice as fast as the global average, melting ice and thawing permafrost. Arctic sea ice has been shrinking more rapidly, falling to its lowest volume and second lowest area on record during the 2011 summer melt season. With the summertime ice loss outpacing wintertime recovery, Arctic sea ice has thinned, making it increasingly vulnerable to further melting. Scientists expect a completely ice-free summertime Arctic by 2030 or even earlier.

As the reflective ice disappears, it exposes the dark ocean, which more readily absorbs solar energy, further warming the region. This sets forth a climate cascade, accelerating ice loss both in the ocean as well as on nearby Greenland, which contains enough ice to raise global sea level by 7 meters (23 feet) if it completely melted. The warming also thaws Arctic permafrost, releasing carbon dioxide and methane, further accelerating global warming.

Even without fully incorporating such climate feedback, models show that continued reliance on fossil fuels could raise the global temperature by up to 7 degrees Celsius (over 12 degrees Fahrenheit) by the end of this century. Such an elevated temperature would amplify temperature and precipitation extremes enough to make the weather events of recent years look tame in comparison. Only a rapid, dramatic reduction of greenhouse gas emissions can hold future temperatures in a range bearing any resemblance to what civilization has known.

By Janet Larsen and Sara Rasmussen

"Satellite monitoring by the NSIDC in Boulder, Colorado, shows that the melting of sea ice has been unusually fast this year, with as much as 40,000 sq km now disappearing daily.

The melt season started almost a month later than normal at the end of March and is not expected to end until September.

Meanwhile, research from the polar science centre at the University of Washington suggests that the volume of sea ice in March 2010 was 20,300 cubic km, 38% below the 1979 level when records began."

And according to James Hansen, director of the NASA Goddard Institute for Space Studies in New York and one of the world’s most prominent climate scientist, new data also shows that the global surface temperatures may also be at record levels. According to a newly released paper by Hansen and his colleagues the temperature on Earth has for the past 12 months been 0.65C warmer than previous global temperatures from 1951 to 1980. The paper also shows that the global temperature this year will break the previous record from 2005.

"It is likely that the 2010 global surface temperature … will be a record", Hansen writes.

"Global warming on decadal timescales is continuing without let-up … we conclude that there has been no reduction in the global warming trend of 0.15-0.2C/decade that began in the late 1970s."

The Guardian article has written about more findings so be sure to check that article out. Especially worth noting is the new data which shows that January to April this year has been the hottest on record so far. Climate Progress writes:

"Last month tied May 1998 as the hottest on record in the NASA dataset. More significantly, following fast on the heels of easily the hottest April — and hottest Jan-April — on record, it’s also the hottest Jan-May on record.

Also, the combined land-surface air and sea-surface water temperature anomaly for March-April-May was 0.73°C above the 1951-1980 mean, blowing out the old record of 0.65°C set in 2002."

And the temperature records continues! New data also shows that the temperature during January-June this year has been the hottest ever recorded by NASA.

"It’s all the more powerful evidence of human-caused warming “because it occurs when the recent minimum of solar irradiance is having its maximum cooling effect,” as a recent NASA paper notes."

But La Nina conditions might build up during July and August which might reduce the average heat temperature for 2010.

Meteorologist Jeff Masters also notes that new temperature records have been reached in Kuwait, Saudi Arabia, Iraq, Chad, Niger, Pakistan and Myanmar. Masters writes:

"We’ve now had eight countries in Asia and Africa, plus the Asian portion of Russia, that have beaten their all-time hottest temperature record during the past two months. This includes Asia’s hottest temperature of all-time, the astonishing 53.5°C (128.3°F) mark set on May 26 in Pakistan…. This week’s heat wave in Africa and the Middle East is partially a consequence of the fact that Earth has now seen three straight months with its warmest temperatures on record, according to NOAA’s National Climatic Data Center."

Also read:  Hundreds die in Indian heatwave – Death toll expected to rise as India faces record temperatures of up to 122F in hottest summer on record

The World Meteorological Organization (WMO) has in a preliminary report has concluded that last year the global mean temperature was 14.3 °C which makes 2008 “the tenth warmest year on a record that dates back to 1850.”

“The ten warmest years on record have occurred since 1997. Global temperatures for 2000-2008 now stand almost 0.2 °C warmer than the average for the decade 1990–1999.”

Climate scientists at the Met Office Hadley Centre and the Climatic Research Unit (CRU) at University of East Anglia says that the global mean temperature for 2008 “is slightly down on earlier years” due to La Nina, an ocean-atmosphere phenomenon that has a cooling effect on the earth.

“Climate scientists at the Met Office Hadley Centre and the Climatic Research Unit (CRU) at University of East Anglia maintain the global climate record for the WMO. They say this figure is slightly down on earlier years this century partly because of the La Niña that developed in the Pacific Ocean during 2007.

La Niña events typically coincide with cooler global temperatures, and 2008 is slightly cooler than the norm under current climate conditions. Professor Phil Jones at the CRU said: “The most important component of year-to-year variability in global average temperatures is the phase and amplitude of equatorial sea-surface temperatures in the Pacific that lead to La Niña and El Niño events”.”

I wrote about La Nina and the cooling effect it had for global temperatures during the first half of 2008 in September last year. Back then John Kennedy, climate monitoring and research scientist at the Met Office’s Hadley Centre, expected that 2008 would be the 10th warmest year since 1850.

“2008 will still be significantly above the long-term average,” and that “there’s been a strong upward trend in the last few decades, and that’s the thing to focus on,” Kennedy said back then. And it seems he was correct.

The new report concludes that “human influence, particularly emission of greenhouse gases, has greatly increased the chance of having such warm years”.

“Dr Peter Stott of the Met Office says our actions are making the difference: “Human influence, particularly emission of greenhouse gases, has greatly increased the chance of having such warm years. Comparing observations with the expected response to man-made and natural drivers of climate change it is shown that global temperature is now over 0.7 °C warmer than if humans were not altering the climate.”

Calculating the changing risk attributable to human influence is part of an ongoing collaboration between the Met Office Hadley Centre and the University of Oxford. Commenting on the dramatically increased odds of such warm years because of human induced climate change, Dr Myles Allen from Oxford University said: “Globally this year would have been considered warm, even as recently as the 1970s or 1980s, but a scorcher for our Victorian ancestors.”

Beneath the underlying warming, temperature continues to fluctuate from year to year as a result of natural variations. Stott added: “As a result of climate change, what would once have been an exceptionally unusual year has now become quite normal. Without human influence on climate change we would be more than 50 times less likely of seeing a year as warm as 2008.”"

So there you have it. The science, yet again, says that the planet continues to warm up and that human activities are to be blamed.

Newly released data from the UK Met Office shows that during the first half of 2008 the global temperatures was more than 0.1 Celcius cooler than any other year after 2000. The reason for this is La Nina, an ocean-atmosphere phenomenon that has a cooling effect on the earth.

But this doesn’t mean the deniers are correct about anything else. Scientists still expects that 2008 will be the 10th warmest year since 1850. And the UK Met Office says that the global temperatures will continue to rise again when La Nina eases away.

“The big thing that’s been happening this year is La Nina, which has lowered global temperatures somewhat,” said John Kennedy, climate monitoring and research scientist at the Met Office’s Hadley Centre.

“La Nina has faded in the last couple of months and now we have neutral conditions in the Pacific,” he told BBC News.

Dr Kennedy also said that “2008 will still be significantly above the long-term average,” and that “there’s been a strong upward trend in the last few decades, and that’s the thing to focus on.”

Even during the temporarily cooling effect from La Nina we see evidence that the rapid man-made warming continues. Images from National Aeronautics and Space Administration satellites show continued breakup of 2 of Greenland’s largest glaciers. According to Canadian authorities the Northwest Passage is navigable. Recently scientists warned that the Arctic could become ice-free during the summers as early as 2013. And just yesterday a huge chunk of ice shelf nearly the size of Manhattan broke away in Canada’s northern Arctic.

Climate deniers have, of course, been acting like crazy about this. But is it true? Are the climate deniers correct? Can we finally breathe out? Have the scientists been wrong all this time?

Unfortunately, that’s not the case.

To be able to see a real trend in global warming you must study the temperature under a long time span to be able to see if the temperatures are increasing or not. And the trend is clear – the temperatures are increasing. The chart above clearly shows how temperature increases from year to year (the red line) and the trend (the blue lines).

It’s worth noting that the warming has increased faster the last 10 years than before.

The global temperatures are still increasing but have been slowed down this winter a bit due to La Niña. This ocean-atmosphere phenomenon has a cooling effect on the earth.

During the La Niña period sea surface temperature across the equatorial Eastern Central Pacific Ocean will be lower than normal by 0.5 °C. La Niña is similar to El Niño but where La Niña cools down the planet El Niño increase the global temperature by at least 0.5 °C.

“However, since the end of April, the La Nina event has taken some of the heat out of what could have been an even warmer year”, Phil Jones, director of the Climatic Research Unit at the University of East Anglia (UEA), said. So even that La Nina has been around this year with it’s cooling effects the temperatures have kept rising.

The 11 warmest years have all occurred within the last 13 years. The Hadley Centre ranks this year as the seventh warmest.

Vicky Pope, head of climate prediction at the Hadley Centre, says that the data “confirmed the need for swift action to combat further rises in global temperatures because of human behaviour.”

Learn more about the Hadley Centre for Climate Prediction and Research over at Wikipedia.

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