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Detecting, over time, a definite trend in the direction of change in the global climate: Is it really happening?

Detecting, over time, a definite trend in the direction of change in the global climate: is it really happening?

Short answer

The Synthesis Report based on the fourth assessment of the Intergovernmental Panel on Climate Change (2007) reports, “Warming of the climate system is unequivocal.”

Detailed answer

This conclusion is now evident from observations of atmospheric and oceanic temperature. Global surface temperature, includes both surface air temperature measurements at terrestrial weather stations and sea surface temperature measurements from ships and satellites. Temperatures from each station are averaged over day and night as well as throughout the seasons of the year. The results show a global average surface temperature increase of 1.4°F (0.78°C) since 1905, with about 1.1°F (0.61°C) of the increase occurring since the mid 1970’s. Nine of the ten warmest years ever recorded occurred during the past decade. The average increase in sea surface temperatures has been about half that of air temperatures.

Other changes in climate have been observed such as changing precipitation patterns, drought and floods, storm intensity, polar and glacial ice melt and seasonal disruptions of terrestrial ecosystems. Predicting these regional changes with climate models is difficult and incomplete, so questions remain as to how correlated these changes are with respect to increasing greenhouse gases in the atmosphere.

Rain and snow patterns have shifted during the past century. Precipitation has increased in eastern parts of North and South America, northern Europe and central Asia but has declined in the Mediterranean, parts of Africa and southern Asia.

There is good evidence for an increased intensity of tropical cyclonic storms in the north Atlantic with less convincing evidence elsewhere. There is no clear indication of an increased frequency of tropical cyclones.

A decrease in the extent of polar ice and snow is evident. Late summer Arctic sea ice is shrinking at the rate of about 8% per year and may result in an ice clear summer Arctic Ocean in 20 to 30 years.

Melting of Greenland’s ice sheet is speeding up. NASA satellite data show the melting rate has accelerated since 2004. Estimated monthly changes in the mass of Greenland's ice sheet suggest it is melting at a rate of about 239 cubic kilometers (57.3 cubic miles) per year. There is no clear evidence that this rate will be maintained or that the ice sheet will stabilize. Since Greenland ice contains about as much water as the Gulf of Mexico or something of the order of 600,000 cubic miles, there appears to be little danger of a complete meltdown in the next century. Other ice systems are also melting at an accelerating rate. This loss of glacier ice is evident for most of the world’s glaciers. Perhaps the most dramatic glacier withdrawal has been in the Alps, where it has occurred in full view of residents and tourists. An 1859 etching of the Rhone glacier in the Canton of Valais, Switzerland shows the ice filling the valley. In 2001 the glacier was nearly out of sight, 2.5 km (1.6 miles) distant and 450 meters (1500 feet) higher.

Sea level has been rising about 1 to 2 centimeters per decade due to the water gained from the melting of ice caps, ice fields, and mountain glaciers in addition to the thermal expansion of ocean water. Recent studies indicate that about 12% of this rise comes from ice shedding from the Greenland and Antarctica ice sheets. The remaining 88% is due to the expansion of warming sea water and melting from mountain glaciers and other ice caps. This rise is consistent with the general warming of the Earth system.

Because climate is quite a chaotic phenomenon involving a multitude of effects, not every year will be warmer than the last or will other weather events such as hurricane intensity or ice melting increase annually in a smooth fashion. However the modeled trends are certainly consistent with what might be expected from the increase in the observed atmospheric greenhouse warming. For example, while some regions of Antarctica, particularly the peninsula that stretches toward South America, have warmed in recent years, weather stations in other regions of Antarctica, including the one at the South Pole, have recorded a cooling trend. Recent studies however now show that there is warming across the whole continent--stronger in winter and spring but it is there in all seasons. "These data indicate the eastern region of the continent, which is larger and colder than the western portion, is warming at 0.1C per decade, while the west is warming at 0.17C per decade – faster even than the global average.

Questions & Answers

what is variations in raman spectra for nanomaterials
Jyoti Reply
I only see partial conversation and what's the question here!
Crow Reply
what about nanotechnology for water purification
RAW Reply
please someone correct me if I'm wrong but I think one can use nanoparticles, specially silver nanoparticles for water treatment.
yes that's correct
I think
what is the stm
Brian Reply
is there industrial application of fullrenes. What is the method to prepare fullrene on large scale.?
industrial application...? mmm I think on the medical side as drug carrier, but you should go deeper on your research, I may be wrong
How we are making nano material?
what is a peer
What is meant by 'nano scale'?
What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is simplest way to understand the applications of nano robots used to detect the cancer affected cell of human body.? How this robot is carried to required site of body cell.? what will be the carrier material and how can be detected that correct delivery of drug is done Rafiq
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Global climate change. OpenStax CNX. Sep 14, 2009 Download for free at http://cnx.org/content/col10704/1.4
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