There is no single thermometer measuring the global temperature. Instead, individual thermometer measurements taken every day at several thousand stations over the land areas of the world are combined with thousands more measurements of sea surface temperature taken from ships moving over the oceans to produce an estimate of global average temperature every month (see the sections on how climate is measured ).
From these records, the ten warmest years in the instrumental record of global temperature (since around 1880) all occur within the 12 year period 1997-2008. Although 2008 data below show it was the coolest since 2000 due to the moderate to strong La Niña that developed in the latter half of 2007. However, the total global temperature increase from the 1850s through to 2005 is 0.76°C (1.36°F) and the rate of warming averaged over the last 50 years is nearly twice that for the last 100 years. So don’t be lulled by one year where it is relatively cooler, what we need to look at is decadal or long term trends.
An increasing rate of warming has taken place over the last 25 years. Above the surface, global observations since the late 1950s show that the troposphere (up to about 10 km) has warmed at a slightly greater rate than the surface, while the stratosphere (about 10–30 km) has cooled markedly since 1979. This is in accord with physical expectations and most model results.
Confirmation of a global temperature rise comes from the observed temperature increases in the oceans, observations of sea level rise, glacial melt, sea ice retreat in the Arctic and diminished snow cover in the Northern Hemisphere. Global average temperature is forecast to rise 4°C (7.2°F) toward the end of the 21st century, and this is a mere 90 years away! Even if began today, and stopped most of our greenhouse gas emissions overnight, we would still see a temperature rise of around 2°C (3.6°F) by 2090-2100. David Spratt and Philip Sutton explain in their paper Code Red what will happen with three degrees of warming, and how dangerous this is.
This rapid rise in temperature is unmatched in the last million years, and even then, the data indicate that the global warming at the end of an ice age was a gradual process taking about 5,000 years. Our human ( anthropogenic ) actions have ramped up the rate of change not evidenced in any record, and we are leaving ourselves very little time to adapt.
Figure Above: Annual average global temperature (black dots) along with simple fits to the data. The left hand axis shows global temperature anomalies relative to the 1961 to 1990 average and the right hand axis shows the estimated actual temperature (°C). Linear trend fits to the last 25 (yellow), 50 (orange), 100 (purple) and 150 years (red) are shown, and correspond to 1981 to 2005, 1956 to 2005, 1906 to 2005, and 1856 to 2005, respectively. Note that for shorter recent periods, the slope is greater, indicating accelerated warming.
The 4th IPCC Report also states that, “analysis of long-term changes in daily temperature extremes has recently become possible for many regions of the world (parts of North America and southern South America, Europe, northern and eastern Asia, southern Africa and Australasia). Especially since the 1950s, these records show a decrease in the number of very cold days and nights and an increase in the number of extremely hot days and warm nights. The length of the frost-free season has increased in most mid- and high-latitude regions of both hemispheres. In the Northern Hemisphere, this is mostly manifest as an earlier start to spring.”
Regional Temperature Anomalies
2008 was a year with above-average temperatures all over Europe. A large geographical domain, including north-western Siberia and part of the Scandinavian region, recorded a remarkably mild winter. January and February were very mild over nearly all of Europe. Monthly mean temperature anomalies for these months exceeded +7°C in some places in Scandinavia. In most parts of Finland, Norway and Sweden, winter 2007-08 was the warmest recorded since the beginning of measurements. In contrast, the boreal winter was remarkably cold for a large part of Eurasia extending eastward from Turkey to China. Some places in Turkey had their coldest January nights in nearly 50 years. This extreme cold weather caused hundreds of casualties in Afghanistan and China.
In January 2009 Melbourne experienced three successive days of temperatures above 43°C for the first time in recorded history. In March 2008, southern Australia experienced a record heatwave that brought scorching temperatures across the region. Adelaide experienced its longest running heatwave on record, with 15 consecutive days of maximum temperatures above 35°C. Persistent extreme heat affected much of eastern Australia from late December 2005 until early March with many records being set (e.g. second hottest day on record in Sydney with 44.2°C/111.6°F on 1 January). Spring 2006 (September-November) was Australia’s warmest since seasonal records were first compiled in 1950. Heat waves were also registered in Brazil from January until March 2006 (e.g. 44.6°C/112.3°F in Bom Jesus on 31 January – one of the highest temperatures ever recorded in Brazil).
Several parts of Europe and the USA experienced heat waves with record temperatures in July and August of 2006. Air temperatures in many parts of the USA reached 40°C/104°F or more. The July European-average land-surface air temperature was the warmest on record at 2.7°C above the climatological normal.
Autumn 2006 (September-November) was exceptional in large parts of Europe at more than 3°C warmer than the climatological normal from the north side of the Alps to southern Norway. In many countries it was the warmest autumn since official measurements began: records in central England go back to 1659 (1706 in The Netherlands and 1768 in Denmark).
Arctic sea ice extent during the 2008 melt season dropped to its second-lowest level since satellite measurements began in 1979, reaching the lowest point in its annual cycle of melt and growth on 14 September 2008. Average sea ice extent over the month of September, a standard measure in the scientific study of Arctic sea ice, was 4.67 million km2. The record monthly low, set in 2007, was 4.3 million km2.
Based on science from the IPCC 4th Report, and consistent with observed increases in global temperature, there have been:
– decreases in the length of river and lake ice seasons.
– worldwide reduction in glacial mass and extent in the 20th century.
– melting of the Greenland Ice Sheet has recently become apparent.
– snow cover has decreased in many Northern Hemisphere regions.
– sea ice thickness and extent have decreased in the Arctic in all seasons.
– the oceans are warming
– sea level is rising due to thermal expansion of the oceans and melting of land ice.
The rapid rise in global temperature is unmatched in the last million years. Normally, and when the Earth has warmed after an ice age, it is a gradual process taking about 5,000 years.
What Other Visitors Have Said
Click below to see contributions from other visitors to this page…
Mr. Hot Core Earth Dot Come
Why are the Oceans getting warmer? I could understand the air temp, land temp even, BUT NOT THE OCEAN TEMPS…with pole ice melting the sea should be getting …
plz plant more trees
I like to ask each and every one to plant a greater number of trees. I have an idea that each and every one needs to plant “TREES ON THEIR BIRTH DAY”. If …
SAVE THE WORLD!!!!
buy a hybrid
change light bulbs
turn the AC down
please our world is dying so ……..get off your asses and save it!!!!
So if there is an increase of .04 C in 40+ years in global warming as a natural earth cycle along with the effects of urbanization, is the fear factor …
Climate is Changing Faster!
The CSIRO report that came out in Nov 2007, supports the idea that climate is changing faster than is being predicted by the United Nations Intergovernmental …
Global Temperature – The Consequences
The weather is not a feature we can easily predict. Even with all our technology the weatherman seems to get it wrong and there has been an increase in …
I’ve recently visited the glacier, and it’s interesting to see how the ice has receded dramatically. There are signs marking the position of the glacier’…
as the story moderates and the panic wears off Not rated yet
I recall being told in 1970 that New York would be partly submerged by the mid 1990s. I recall being told that ozone would kill us all when the ozone …
Dr Arnold MANN MB BS FRCS (Eng) FRACS Not rated yet
I thought it was now agreed that global temperature had ceased to rise since circa 1998. Why do your graphs show the opposite?
I can average the temperature …
Robert Weigel, Engineer @ Sound Doctorin’ Not rated yet
Get some current DATA people, unless DATA is against your religion or something I guess. Seriously if someone is supposedly on top of this issue, why is …
Tanzania learn Not rated yet
Most of African countries especially Tanzania had a cool temp earlier but to now things are getting worse because people are very ignorant about the weather …
Temperature Readings Not rated yet
Please Explain ! Not rated yet
How does carbon dioxide heat the earth?
The argument goes that carbon dioxide can absorb infra-red radiation emitted from the earth and hence it becomes …
Ice Core Graphs for last 47,000 Years Not rated yet
“The rapid rise in global temperature is unmatched in the last million years. Normally, and when the Earth has warmed after an ice age, it is a gradual …
National Academy statistics Not rated yet
Glacial-Interglacial cycles A great 400,000 year chart of climate change cycles. notice “.gov”
global warming Not rated yet
We must all be worried about the potential hazardous impacts of global warming. we can have our share to minimize it. Not yet too late…..thanks
OBSERVATION THE GREATEST WEATHER INSTRUMENT Not rated yet
Gesare Okemwa was born in the 1920s.She doesn’t need scientific explanation to concur that climate change is here. To her observation and comparison of …
GREEN HOUSE GASES Not rated yet
Reduce or minimise green house emissions by turning to solar power
Not Supported Not rated yet
I am interested in how these temperature records were obtained. We have only been keeping accurate temperature records fairly recently. According to some …
THE CONVENIENT TRUTH Not rated yet
You should all be worried. Existing records reveal an increase in high-latitude sea surface temperatures (SSTs) (8° to 10°C) and in bottom water temperatures …
Systems engineer Not rated yet
Has the accuracy of air temperature devices used to determine mean world temperature changed over the 150 years or so in the survey bound? Has the number …
Missing info Not rated yet
What about the huge amount of warming between 2005 and 2009? Oh, nevermind.
Global Warming Not rated yet
When I was a kid , I used to feel more chilly-ness in Delhi as compared to the present time, I used to enjoy summer, winter seasons but now the winter has …
science teacher Not rated yet
In the midwest alone, I have noticed that the seasons seem to be blending more each year. This year we have not had much of a summer when there should …
Gas Flaring and Global Warming Not rated yet
Gas flares in Nigeria are grave and to a great extent have contributed the global warming. statistics hold that 75% of the total gas produced in nigeria …
Global Warming Not rated yet
Global warming is happening because people do not care about our planet for what is happening to it. We are idiots and that is the truth. While some people …
Why, Oh why? Not rated yet
Im scared for my life and my kids and my grand kids, ect??
I’m definiatly gonna buy a hybrid!!!!
And save up to put solar panals on my house.
Global Warming Not rated yet
Well in Inuvik we are experiencing warming tempratures. Here in Inuvik in the summer as well as winter it is cold here! The animals are coming more up …
COUNT DOWN BEGINS TO END ! Not rated yet
Count down has begun for the Death of the Blue Planet! Next 100 years is a crucial period how do we save the planet from climate change. It took millions …