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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 does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
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
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
s. Reply
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
SUYASH Reply
for screen printed electrodes ?
SUYASH
What is lattice structure?
s. Reply
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
China
Cied
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
Porter
many many of nanotubes
Porter
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Yasmin
what is the function of carbon nanotubes?
Cesar
I'm interested in nanotube
Uday
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
what is nano technology
Sravani Reply
what is system testing?
AMJAD
preparation of nanomaterial
Victor Reply
how to synthesize TiO2 nanoparticles by chemical methods
Zubear
how did you get the value of 2000N.What calculations are needed to arrive at it
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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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