Causes of climate change and Canada (disambiguation): Difference between pages

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{{See|Global warming}}

'''Canada''' generally refers to the country in North America, derived from an [[Iroquois]] word meaning "village" or "settlement."

{{portal|energy}}

'''Attribution of recent climate change''' is the effort to scientifically demonstrate which mechanisms are responsible for observed changes in the [[Earth]]'s [[climate]]. The endeavor centers on the observed changes over the last century and in particular over the last 50 years, when observations are best and human activity greatest. The latest [[Intergovernmental Panel on Climate Change]] (IPCC) report concluded that,

:"Most of the observed increase in globally averaged temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations." [http://www.ipcc.ch/SPM2feb07.pdf].

#REDIRECT [[Turkey]]

The report defines "very likely" as a greater than 90% probability and represents the [[Scientific opinion on climate change|consensus]] of the scientific community.

==Geography==

===Historical locales===

Canada may refer to historical regions now subsumed by Canada:

* [[Canada, New France]], a French colony along the St. Lawrence River

* [[The Canadas]], British colonies:

** [[Upper Canada]]

** [[Lower Canada]]

* The united [[Province of Canada]], formed from Upper and Lower Canada which then became [[Canada West]] and [[Canada East]] respectively

===Current locales===

== Attribution of 20th century climate change ==

* [[Upper Canada Village]], a heritage park near Morrisburg, Ontario

[[Image:Climate Change Attribution.png|250px|right|thumb|One [[global climate model]]'s reconstruction of temperature change during the 20th century as the result of five studied forcing factors and the amount of temperature change attributed to each.]]

* [[City of Canada Bay]], in Sydney, New South Wales, Australia

** [[Canada Bay, New South Wales]], a suburb of the city

* [[Canada Creek Ranch, Michigan]], USA

* [[Canada Glacier]], in [[Antarctica]]

* [[Canada, Hampshire]], in England

* [[Canada, Kansas]], USA, a township in Labette County

* [[Canada, Kentucky]], USA

* [[Canada, North Carolina]], USA, a township in Jackson County

* [[Canada Park]], a region of the West Bank

* [[Little Canada, Minnesota]], USA

* [[New Canada, Maine]], USA

* [[West Canada Creek]], a small river in upstate New York, USA

* Barque Canada Reef, part of the disputed [[Spratly Islands]] in the [[South China Sea]]

* [[New Canada, Gaborone, Botswana]], a neighbourhood of Gaborone

==Companies==

Over the past 150 years human activities have released increasing quantities of [[greenhouse gas]]es into the [[Earth's atmosphere|atmosphere]]. This has very likely led to increases in mean global temperature, or [[global warming]]. Other human effects are relevant—for example, sulphate [[Particulate|aerosol]]s are believed to lead to cooling—and natural factors also contribute. According to the [[historical temperature record]] of the last century, the Earth's near-surface air temperature has risen around 0.74 [[Plus-minus sign|±]] 0.18 °[[Celsius]] (1.3 ± 0.32 °[[Fahrenheit]]).

*The [[Dominion of Canada General Insurance Company]] is one of the largest insurance companies in [[Canada]]

==Buildings and structures==

An important question in current climate change research is over attribution of climate change to either natural/internal or human factors over the period of the instrumental record—from about 1860, and especially over the last 50 years. In the 1995 second assessment report (SAR) the [[Intergovernmental Panel on Climate Change|IPCC]] made the widely quoted statement that "The balance of evidence suggests a discernible human influence on global climate". The phrase "balance of evidence" suggests the (English) common-law standard of proof required in civil as opposed to criminal courts: not as high as "beyond reasonable doubt". In 2001 the third assessment report (TAR) upgraded this by saying "There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities".[http://www.grida.no/climate/ipcc_tar/wg1/007.htm] The 2007 fourth assessment report (AR4) report strengthened this and noted, "Discernible human influences now extend to other aspects of climate, including ocean warming, continental-average temperatures, temperature extremes and wind patterns".

Buildings and structures with Canada in their name include:

* [[Canada Dock]], a dock on the River Mersey and part of the Port of Liverpool

* [[Canada Square Complex]], three interconnected office buildings located in Toronto

* [[Canada Square]], a square on Canary Wharf, Docklands, Tower Hamlets in east end of London

** [[One Canada Square]], the tallest building in London & Britain, commonly known as the Canary Wharf Tower

* [[Canada Water]], an area in south-east London

** [[Canada Water tube station]], a London Underground station at Canada Water

* A section of the [[Auschwitz concentration camp]] in which property taken from prisoners was sorted, prior to sending to Nazi Germany. The section was named after the country because it was known for an abundance of land, which Canada is also known for, and also because most camp inmates had never been to Canada, and the rest knew little about that country.

==Concepts==

Over the past five decades there has been a global warming of approximately 0.65 °C (1.17 °F) at the Earth's surface (see [[historical temperature record]]). Among the possible factors that could produce changes in global mean temperature are internal variability of the climate system, external forcing, an increase in concentration of greenhouse gases, or any combination of these. Current studies indicate that the increase in greenhouse gases, most notably CO₂, is mostly responsible for the observed warming. Evidence for this conclusion includes:

The term ''Canada'' is associated with the following concepts:

* [[Canada Day]], Canada's national holiday

* [[O Canada]], the country's national anthem

* [[Ô Canada! mon pays, mes amours]], a French Canadian song

* [[Canada (song)|Canada]], a song also known as ''The Centennial Song'', written to celebrate Canada's centennial

* [[Canada (album)|Canada]], an album by Barb Jungr and Michael Parker

* [[Order of Canada]], a civilian honour

* [[HMS Canada (1913)|HMS ''Canada'']], a battleship in the Royal Navy

* [[Remote Manipulator System|Canadarm]] and [[Mobile Servicing System|Canadarm2]], robotic arms that equip the [[Space Shuttle program|US Space Shuttle]] and [[International Space Station]] respectively

==Taxonomy==

* Estimates of internal variability from climate models, and reconstructions of past temperatures, indicate that the warming is unlikely to be entirely natural.

The following species are named for their relation to Canada:

* Climate models forced by natural factors ''and'' increased greenhouse gases and aerosols reproduce the observed global temperature changes; those forced by natural factors alone do not [http://www.grida.no/climate/ipcc_tar/wg1/007.htm].

* [[Canada Buffaloberry]], a shrub of the genus Shepherdia

* "Fingerprint" methods indicate that the pattern of change is closer to that expected from greenhouse gas-forced change than from natural change.[http://www.grida.no/climate/ipcc_tar/wg1/460.htm]

* [[Canada Goose]]

* The plateau in warming from the 1940s to 1960s can be attributed largely to sulphate aerosol cooling.[http://www.grida.no/climate/ipcc_tar/wg1/figspm-4.htm]

* [[Canada Lynx]], a relative of the Eurasian Lynx

* [[Canada Warbler]], a small songbird

* [[Canadia]], an extinct polychaete annelid whose name derives from Canada

==People and organizations==

In 2001, the U.S. [[National Academy of Sciences]] released a report supporting the IPCC’s conclusions regarding the causes of recent climate change. It stated, "Greenhouse gases are accumulating in Earth’s atmosphere as a result of human activities, causing surface air temperatures and subsurface ocean temperatures to rise. Temperatures are, in fact, rising. The changes observed over the last several decades are likely mostly due to human activities, but we cannot rule out that some significant part of these changes are also a reflection of natural variability."[http://www4.nationalacademies.org/onpi/webextra.nsf/web/climate?OpenDocument] [http://www.eia.doe.gov/oiaf/1605/ggccebro/chapter1.html][http://www.eldis.org/static/DOC8822.htm]

* [[Canada Lee]], an actor who pioneered roles for African-Americans

* [[Canada First]], a movement organized in Toronto in the 1870s to promote the creation of a Canadian nationality

* [[Canada (music group)]], folk music group.

==Transportation==

Another candidate mechanism for climate change is [[solar forcing]]. Most [[global climate model]] (GCM) studies indicate that the direct effects of [[solar variation]] would be too small to significantly affect climate. Much of the solar research centers around possible mechanisms to amplify the effect, possibly through increasing solar activity reducing cosmic ray flux and, speculatively, modifying cloud cover;[http://www.sciencemag.org/cgi/content/full/301/5641/1886] however, there is no agreement on whether this is correct within the scientific community. Since GCMs ''can'' reproduce observed temperature trends (including early twentieth century changes, where solar forcing is non-negligible) there is no obvious need for a high sensitivity to solar forcing. Indeed, a significantly higher sensitivity to solar forcing would make early twentieth century temperature change inexplicable.{{Fact|date=February 2007}}

* [[Air Canada]], an airline

** also operates [[Air Canada Jazz]], [[Air Canada Tango]] and others (see [[:Category:Air Canada]])

* [[Canada Dock Branch]], a railway line in Liverpool, England

* [[Trans Canada Trail]], a 18 078 km long trail in Canada

==Media and communications==

===Subsequent to the TAR===

* [[Blame Canada]], a song from the film ''[[South Park: Bigger, Longer & Uncut]]''

Following the publication of the Third Assessment Report (TAR) in 2001, "detection and attribution" of climate change has remained an active area of research. Some important results include:

* [[Boards of Canada]], a Scottish electronic music duo

* [[Canada Now]], an early-evening national news program aired on [[CBC Television]]

* [[Hockey Night in Canada]], a popular television broadcast of National Hockey League games in Canada

* [[Made in Canada]], a Canadian television sitcom, syndicated as The Industry outside Canada

* [[Occupied Canada (Harry Turtledove)|Occupied Canada]], a fictional (alternative) history of the Dominion of Canada since 1863

* [[Report Canada]], a show that aired on [[TVOntario]]

* [[Sounds Like Canada]], a radio program which airs weekday mornings on CBC Radio One

* [[Trans-Canada Network]], now known as [[CBC Radio One]]

==''Cañada''==

* A review of detection and attribution studies by the ''International [[Ad hoc|Ad Hoc]] Detection and Attribution Group'' [http://ams.allenpress.com/amsonline/?request=get-abstract&doi=10.1175%2FJCLI3329.1] found that ''"The evidence indicates that natural drivers such as solar variability and volcanic activity are at most partially responsible for the large-scale temperature changes observed over the past century, and that a large fraction of the warming over the last 50 yr can be attributed to greenhouse gas increases. Thus, the recent research supports and strengthens the IPCC Third Assessment Report conclusion that 'most of the global warming over the past 50 years is likely due to the increase in greenhouse gases.'"''

The Spanish word '''''cañada''''' means "glen" and may be confused with ''Canada''.

* Multiple independent reconstructions of the [[temperature record of the past 1000 years]] confirm that the late 20th century is probably the warmest period in that time

* ''see [[Cañada]]''

* Two papers in Science in August 2005 [http://www.realclimate.org/index.php?p=170] [http://www.realclimate.org/index.php?p=179] resolve the problem, evident at the time of the TAR, of [[troposphere|tropospheric]] temperature trends. The UAH version of the record contained errors, and there is evidence of spurious cooling trends in the radiosonde record, particularly in the tropics. See [[satellite temperature measurements]] for details; and the 2006 US CCSP report [http://www.climatescience.gov/Library/sap/sap1-1/finalreport/sap1-1-final-execsum.pdf].

* Barnett and colleagues <ref>Barnett et al. "Penetration of Human-Induced Warming into the World's Oceans" (Science, Vol 309, Issue 5732, 284-287</ref> say that the observed warming of the oceans ''cannot be explained by natural internal climate variability or solar and volcanic forcing, but is well simulated by two [[anthropogenic]]ally forced climate models. We conclude that it is of human origin, a conclusion robust to observational sampling and model differences'' [http://www.sciencemag.org/cgi/content/abstract/309/5732/284?rbfvrToken=478e88391c8e1ff344f98f5f5d3b62bac11e2a12].

* Bratcher and Giese [http://physics.ramapo.edu/downloads/drew/backup/home/drew/EARTICLES/papers/grl/2002GL015191.pdf] observed conditions that "could be an indication of a climate regime shift to pre-1976 conditions." Bratcher and Giese conclude: "The results presented here do not preclude the possibility that anthropogenic sources of greenhouse gases have contributed to global warming. However the results do indicate that the human forced portion of global warming may be less than previously described."

* The [[IPCC Fourth Assessment Report]] states that human actions are "very likely" the cause of most global warming, meaning a 90% or greater probability that more than 50% of observed warming is attributable to human actions.

* Henrik Svensmark at [[Danish National Space Center]] <ref>[http://www.journals.royalsoc.ac.uk/(23vr0d45z5lsv045bnqadb55)/app/home/contribution.asp?referrer=parent&backto=issue,5,19;journal,4,138;linkingpublicationresults,1:102023,1]</ref> contends that low-level clouds (which cool the Earth) are formed when cosmic rays come into the low atmosphere. <ref>[http://www.spacecenter.dk/research/sun-climate/the-sky-experiment-1]</ref> Previous research has demonstrated a reduction in cosmic rays between 1920 and 1980, when measurements were stopped.{{cn}}

====Geography====

== Detection and attribution ==

* [[Canada de los Alamos, New Mexico]], USA

Detection and attribution of climate signals, as well as its common-sense meaning, has a more precise definition within the climate change literature, as expressed by the IPCC [http://www.grida.no/climate/ipcc_tar/wg1/443.htm#1211].

* [[La Cañada Flintridge, California]], USA

====People====

''Detection'' of a signal requires demonstrating that an observed change is statistically significantly different from that which can be explained by natural internal variability.

* [[David Cañada]], sometimes spelt ''David Canada'', Spanish cyclist

* [[Lisa Canada]], a former Playboy model

* [[Ron Canada]], an American actor and former television newscaster

* [[Tom Canada]], a football player from Visalia, California

==See also==

''Attribution'' requires demonstrating that a signal is:

*[[Canada's name]]

* unlikely to be due entirely to internal variability;

*[[Kanata, Ontario]]

* consistent with the estimated responses to the given combination of anthropogenic and natural forcing

*[[Kanada (disambiguation)]]

* not consistent with alternative, physically plausible explanations of recent climate change that exclude important elements of the given combination of forcings.

*[[Canadian (disambiguation)]]

*[[Upper Canada (disambiguation)]]

*[[Canada Dry]]

{{disambig}}

Detection does not imply attribution, and is easier than attribution. Unequivocal attribution would require controlled experiments with multiple copies of the climate system, which is not possible. Attribution, as described above, can therefore only be done within some margin of error. For example, in the IPCC's [[IPCC Fourth Assessment Report|Fourth Assessment Report]] dated 2007, the statement is made that ''"Most of the observed increase in globally averaged temperatures since the mid-20th century is 'very likely' due to the observed increase in anthropogenic greenhouse gas concentrations."'' where 'very likely' is quantified as more than 90% certain.

[[cs:Kanada (rozcestník)]]

== Scientific literature and opinion ==

[[eo:Canada]]

{{Main|Scientific opinion on climate change}}

[[pl:Canada]]

Some examples of published and informal support for the consensus view:

* The attribution of climate change is discussed extensively, with references to peer-reviewed research, in [http://www.grida.no/climate/ipcc_tar/wg1/439.htm chapter 12] of the IPCC TAR, which discusses [http://www.grida.no/climate/ipcc_tar/wg1/443.htm#1211 The Meaning of Detection and Attribution], [http://www.grida.no/climate/ipcc_tar/wg1/456.htm Quantitative Comparison of Observed and Modelled Climate Change], [http://www.grida.no/climate/ipcc_tar/wg1/458.htm Pattern Correlation Methods] and [http://www.grida.no/climate/ipcc_tar/wg1/460.htm Optimal Fingerprint Methods].

*An essay [http://www.sciencemag.org/cgi/content/full/306/5702/1686] in [[Science (journal)|''Science'']] surveyed 928 [[Abstract (summary)|abstracts]] related to climate change, and concluded that most journal reports accepted the [[Scientific opinion on climate change|consensus]]. This is discussed further in [[scientific opinion on climate change#Surveys|scientific opinion on climate change]].

* A recent paper (Estimation of natural and anthropogenic contributions to twentieth century temperature change, [[Simon Tett|Tett SFB]] et al., JGR 2002), says that "Our analysis suggests that the early twentieth century warming can best be explained by a combination of warming due to increases in greenhouse gases and natural forcing, some cooling due to other anthropogenic forcings, and a substantial, but not implausible, contribution from internal variability. In the second half of the century we find that the warming is largely caused by changes in greenhouse gases, with changes in sulphates and, perhaps, volcanic aerosol offsetting approximately one third of the warming." [http://groups-beta.google.com/group/sci.environment/msg/aa8521b67cd216ac?dmode=source]

* In 1996, in a paper in [[Nature (journal)|''Nature'']] titled "A search for human influences on the thermal structure of the atmosphere", [[Benjamin D. Santer]] et al. wrote: "The observed spatial patterns of temperature change in the free atmosphere from 1963 to 1987 are similar to those predicted by state-of-the-art climate models incorporating various combinations of changes in carbon dioxide, anthropogenic sulphate aerosol and stratospheric ozone concentrations. The degree of pattern similarity between models and observations increases through this period. It is likely that this trend is partially due to human activities, although many uncertainties remain, particularly relating to estimates of natural variability." This earlier work only addressed the most recent period. Estimates of natural variability matter for assessing the significance of the trend.

* Some scientists noted for their somewhat skeptical view of global warming accept that recent climate change is mostly anthropogenic. [[John Christy]] has said that he supports the [http://www.agu.org/sci_soc/policy/climate_change_position.html American Geophysical Union (AGU) declaration], and is convinced that human activities are the major cause of the global warming that has been measured. [http://sfgate.com/cgi-bin/article.cgi?file=/c/a/2003/12/18/MNGNV3PH9D1.DTL&type=printable]

Some scientists do disagree with the consensus: see [[list of scientists opposing global warming consensus]]. For example [[Willie Soon]] and [[Richard Lindzen]]<ref>Can increasing carbon dioxide cause climate change?", Lindzen RS, 1997, PNAS 94(16) {{doi|10.1073/pnas.94.16.8335}}</ref> say that there is insufficient proof for anthropogenic attribution. Generally this position requires new physical mechanisms to explain the observed warming; for example "Climate hypersensitivity to solar forcing?", Soon W et al., 2000, Annales Geophysicae-Atmospheres Hydrospheres and Space Sciences 18(5).

== Findings that complicate attribution to CO₂ ==

=== Warming sometimes leads CO₂ increases ===

Factors other than increased CO₂ concentrations can initiate warming or cooling episodes (see e.g., [[orbital forcing]]). The ice core record shows that on some occasions temperature starts rising hundreds of years before CO₂ increases.<ref>{{cite journal |last=Indermühle|first=Andreas|coauthors=Eric Monnin, Bernhard Stauffer, Thomas F. Stocker,Martin Wahlen |date=2000 |title= Atmospheric CO2 concentration from 60 to 20 kyr BP from the Taylor Dome ice core, Antarctica |journal=[[Geophysical Research Letters]] |volume=27|url=http://www.climate.unibe.ch/~stocker/papers/indermuehle00grl.pdf}}</ref> <ref>{{cite journal |last=Fischer|first=Hubertus|coauthors=Martin Wahlen, Jesse Smith, Derek Mastroianni, Bruce Deck |date=1999 |title=Ice core records of atmospheric CO2 around the last three glacial terminations |journal=[[Science (journal)|Science]]|volume=283|doi=10.1126/science.283.5408.1712}}</ref> Such results confirm that the relationship between CO₂ and climate can go in both directions: changes in CO₂ concentrations affect climate, while changes in climate can affect CO₂ concentrations. One proposed mechanism for this effect is increased release of sequestered CO₂ from oceans as circulation patterns shift, perhaps abruptly, in response to climate change.<ref>{{cite journal |last=Skinner|first=L.C.|date=2006 |title= Glacial – interglacial atmospheric CO2 change: a simple “hypsometric effect” on deep-ocean carbon sequestration? |journal=[[Climate of the Past Discussions]] |volume=2|url=http://www.copernicus.org/EGU/cp/cpd/2/711/cpd-2-711_p.pdf}}</ref> <ref>{{cite journal |last=Paillard|first=Didier|date=2000 |title= Glacial Cycles: Toward a New Paradigm |journal=[[Reviews of Geophysics]] |volume=39:3|url=http://www.geog.ox.ac.uk/~mnew/teaching/Online_Articles/paillard_rev_geophys_2001.pdf}}</ref>

A more speculative and polemical inference sometimes drawn is that the causal relationship between temperature rises and global CO₂ concentrations are only one-way, so that historical increases in CO₂ have been nothing more than the product of independently rising temperatures.[http://en.wikipedia.org/wiki/The_Great_Global_Warming_Swindle] However, a strictly "one-way" view of the relationship between CO₂ and temperature contradicts basic results in physics, specifically the fact that the absorption and emission of infrared radiation by CO₂ increases as its atmospheric concentration increases.<ref>{{cite book

|last = Liou

|first = K.N.

|title = An Introduction to Atmospheric Radiation (2nd ed)

|publisher = Academic Press

|year = 2002

|isbn = 978-0124514515}}

</ref><ref>{{cite journal

|last = Staley

|first = D.O.

|coauthors = G.M. Jurica

|journal = Journal of Applied Meteorology

|date = 1970

|title = Flux emissivity tables for water vapor, carbon dioxide and ozone

|volume = 9

|pages = 365–372

|url = http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F1520-0450(1970)009%3C0365%3AFETFWV%3E2.0.CO%3B2}}

</ref>

First principles as well as empirical observation suggest that positive feedbacks from CO₂ concentrations amplify warming initially caused by other factors:

<blockquote>Close analysis of the relationship between the two curves [i.e., temperature and CO₂] shows that, within the uncertainties of matching their timescales, the temperature led by a few centuries. This is expected, since it was changes in the Earth’s orbital parameters (including the shape of its orbit around the Sun, and the tilt of Earth’s axis) that caused the small initial temperature rise. This then raised atmospheric CO2 levels, in part by outgassing from the oceans, causing the temperature to rise further. By amplifying each other’s response, this “positive feedback” can turn a small initial perturbation into a large climate change. There is therefore no surprise that the temperature and CO2 rose in parallel, with the temperature initially in advance. In the current case, the situation is different, because human actions are raising the CO2 level, and we are starting to observe the temperature response. [http://www.antarctica.ac.uk/News_and_Information/news_stories/story.php?id=50] </blockquote>

Present CO₂ levels greatly exceed the range found in the ice core data. Isotopic analysis of atmospheric CO₂ confirms that fossil fuel burning is the source of most of the CO₂ increase, unlike during prior interglacial periods.<ref>{{cite journal |last=Schimel|first=D.|date=1996 |title= CO2 and the carbon cycle, pp.76-86 in Climate Change 1995: The Science of Climate Change. J.T. Houghton, L.G. Meira Filho, B.A. Callander, N. Harris, A. Kattenberg and K. Maskell (eds), Cambridge University Press 1996.|}}</ref> As noted above, models that include increased CO₂ levels when simulating recent climate match the observed data far better than those that do not.[http://www.ipcc.ch/SPM2feb07.pdf]

===Warming elsewhere in the solar system===

In the last 10 years evidence of local or planetary warming has been observed on [[Mars]] [http://news.nationalgeographic.com/news/2007/02/070228-mars-warming.html], [[Pluto]] [http://web.mit.edu/newsoffice/2002/pluto.html], and [[Neptune]]'s largest moon [[Triton (moon)|Triton]] [http://web.mit.edu/newsoffice/1998/triton.html]. It has sometimes been asserted in the popular press that this points to a solar explanation for the recent warming on Earth.{{Fact|date=June 2007}} Climatologists and astronomers disagree with this assertion, stating "the idea just isn't supported by the theory or by the observations"[http://news.nationalgeographic.com/news/2007/02/070228-mars-warming_2.html] and "That's nuts...It doesn't make physical sense that that's the case."[http://www.livescience.com/environment/070312_solarsys_warming.html] Jay Pasachoff, an astronomy professor at Williams College, said that Pluto's global warming was "likely not connected with that of the Earth. The major way they could be connected is if the warming was caused by a large increase in sunlight. But the solar constant—the amount of sunlight received each second—is carefully monitored by spacecraft, and we know the Sun's output is much too steady to be changing the temperature of Pluto."[http://web.mit.edu/newsoffice/2002/pluto.html] Instead, scientific opinion is that these changes are caused by other factors, such as orbital irregularities or (in the case of Mars) changes in [[albedo]] as a result from dust storms.<ref>{{cite web | title=Dust Storms Fuel Global Warming on Mars | first=Ker Than | publisher=Yahoo! News | date=[[4 April]] [[2007]]}}</ref>

==Footnotes==

{{Reflist}}

== References ==

* Le Quéré, ''How much of the recent ''CO₂'' increase is due to human activities?'', 2005 [http://www.realclimate.org/index.php?p=160]

== External links ==

*[http://www.realclimate.org/ RealClimate] - Blog on current climate change issues by active climatologists

*"The Climate of Man", ''The New Yorker'' (2005): [http://www.newyorker.com/printables/fact/050425fa_fact3 Part 1], [http://www.newyorker.com/printables/fact/050502fa_fact3 Part 2], [http://www.newyorker.com/printables/fact/050509fa_fact3 Part 3]

*[http://www.sciencebits.com/CO2orSolar Anthropogenic or Solar?] by Shaviv

*[http://www.epa.gov/climatechange US EPA climate change and global warming website]

{{global warming}}

[[Category:Global warming]]