A controversial theory, supported by the IPCC, UN and most scientific organisations, both governmental and NGOs, concerning the cumulative impact of human activities which is causing a significant change to the composition of the atmospheric gases, with the consequence of changes to the global climate stability.
The policy of ScienceLibrary.info is to present the facts, and let the scientific evidence dispel the myths which have taken hold in the public arena. These myths are:
There is hard evidence that average global temperatures have been rising since the advent of the Industrial Revolution (towards the end of the 18th century), when largescale combustion of fossil fuels began.
NASA's Goddard Institute for Space Studies (GISS) has been analysing data from a global network of meteorological stations, ships and satellites, since the 1970s, and currently holds what is possibly the most comprehensive record of Earth surface, ocean and atmospheric temperatures. Their findings are conclusive:
Taking the average temperature for the years 1951-80 as a baseline for comparison, GISS has prepared the above maps, which show how much deviation there is in the two decades, 1970-79 and 2000-09. All of the deviations are positive, and at an increasing rate of increase. This observation is exactly in line with the theory that greenhouse gases from human activities are responsible for the retention of heat by the Earth, the so-called 'Greenhouse Effect'.
Solar activity, aerosols, and C02 are all modelled against this data to determine the correlations. The conclusion is inevitably the same: the increase in temperature is real and is due to the changes in balance between the amount of energy the Earth receives from the Sun, and the amount it radiates back into space. The incoming radiation varies very little, but the amount of energy re-radiated has changed significantly. This change cannot be correlated to the variations in solar activity. The conclusion is that the cause is changes to the composition of the atmospheric gases.
The map (courtesy of NASA GISS, 2006) is a coloured representation of temperature anomalies. The blue and red colouring graphically represent temperature variations from the baseline reference, which is the mean between 1951 and 1980.
It can be seen that the general trend is towards unevenly distributed warming of the globe, with the polar regions receiving more than the average increase in temperature.
This data matches the models and reports released by the IPCC, the Intergovernmental Panel on Climate Change, established in 1992 by the UNO to study the science and report measurements, and make predictions about, climate change.
Involving 1,200 authors, and reviewers from 113 nations, the current prediction is for a warming of the Earth's oceans and atmosphere by at least 0.2 °C per decade. The report is unanimous that the bulk of the cause is due to human activities, primarily fossil fuel burning and deforestation.
It should be noted that in general detractors from the climate change scenario have been unable to provide any substantial scientific evidence of their own, and have relied on emphasising the uncertainties and lack of data in the IPCC reprots, and other climate change reports and studies. As time has gone on, the scientific evidence has consistently supported the conjecture of anthropogenic source of accelerated global warming, and the position of the detractors has become less and less tenable.
With climate change an accepted fact, the denialists have changed strategy to delay moves to counter the causes by debating the nebulous economic and political issues, rather than the scientific reality. The only sector which stands to gain from delaying action to curb greenhouse gas emissions is those with vested interests. In the US, these are powerful lobby groups, primarily fossil fuel energy companies.
|Kraftwerksart||CO2 pro kWh (g)|
|Kernkraftwerk||10 - 30|
|Wasserkraft||10 - 40|
|Windenergie||10 - 40|
|Photovoltaik||50 - 100|
|Erdgas||400 - 550|
|Steinkohle||790 - 1080|
|Braunkohle||980 - 1230|
|Deutschland Strom-Mix (2007)||604|
Quellen: Süddeutsche Zeitung 2007, Bundesministerium BMWI, World Nuclear Association
|Gesamterzeugung aller Kraftwerke in TWh||636,5||610,6|
|Strom-Mix g pro kWh||604||61|
|Gesamt-CO2 in Milliarden kg||384||37|
|Anzahl der großen thermischen Kraftwerksblöcke||70||15|
|Anzahl der Kernkraftwerksblöcke||17||58|
Climatologists study the Earth's past and present climate. They collect data about the Earth's past from a number of sources. There is geological evidence, and deep ice brought up as kilometer-long cores reveal much about the atmospheric gases of up to half a million years ago. They use floral and faunal records, and study the processes during and between glacial eras. Isotopes can be found in sediments, and these reveal a variety of facts about past sea levels and solar radiation.
The number of variables involved in the climate is truly awe-inspiring. Computers are a vital tool in developing models to try to understand the complexities. As these models are created, new data can test their accuracy, and they can be adjusted over time to give ever preciser models. This is the area of computational science, in which computers can teach themselves about the models, and to some extent develop them independently of human 'tweaking', which could be biased or too focussed on certain issues.
IPCC stands for the United Nations appointed InterGovernmental Panel on Climate Change. The panel was established in 1988 by the WMO (World Meteorological Organization) and UNEP (United Nations Environment Programme), and has the mandate to collect scientific data concerning anthropological climate change, and make reccomendations based on its findings. It has released 5 reports:
These reports support the UNFCCC (United Nations Framework Convention on Climate Change), the principal treaty for coordinating international response to the threat of climate change. The aim of the UNFCCC is: "to stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic [i.e., human-induced] interference with the climate system".
To support this aim, the IPCC investigates the "the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation." It does this by collating findings from a broad range of scientific publications, from thousands of scientifically-qualified authors. It upholds the peer-reviewed requisite for sources.
The IPCC reports also contain a "Summary for Policymakers", involving the approval of more than 120 governments.
In recognition of the outstanding quality of work, and its vital importance, in the face of fossil fuel industry anti-propaganda tactics and American vested interest obstruction and denial, the IPCC was awarded the 2007 Nobel Peace Prize, shared with Al Gore, also a high-profile climate change activist. The award of the Peace Prize was also an acknowledgement that destabilising climate is a major cause of human socio-economic distress, deprivation, displacement, and political breakdown and consequent war.
The Kyoto Protocol is a 1997 agreement, which is part of the 1992 UNFCCC, United Nations Framework Convention on Climate Change, 1992.
A protocol is a supplemental treaty or agreement to an initial treaty. The UNFCCC (United Nations Framework Convention on Climate Change, 1992) set out a general framework for greenhouse gas emission reductions. More specific individual targets, provisions and regulations, were nutted out and set down in the Kyoto Protocol, 1997. Playing its part as perennial obstruction to international consensus, the USA demonstrated the principle that signing the original treaty does not oblige a state to sign and ratify the subsequent protocols, thereby undermining the will and spirit of the other 192 states who did sign and ratify both the treaty and subsequent protocol.
One of the most-known predictions by the IPCC is the potential rise in sea level with rise in global average temperature. The most recent report puts the expected rise in global temperature by 2050 at between 2 and 3°C relative to the start of the Industrial Revolution (when fossil fuels were started to be used en masse). The prediction is for a 59cm rise in sea level.
The precision of the prediction belies the fact that there is a great deal of uncertainty involved. This is due to unknowns such as the rate of ice melt. Jim Hansen, of NASA/GISS, has a far more dramatic expectation: a sea level rise of 25m at 3°C temperature increase, and in a much shorter timeframe. This estimate is based on studies of ice melt in the polar regions, which may not occur linearly with temperature rise, but 'flip' states, suddenly changing from solid ice to water, and causing considerable sea level rise in short time.
2% of global water is ice and snow, so if this enters the oceans, and the average sea depth is 3800m, a rise of 76m is anticipated, In addition, since the oceans are warmer, there will be an expansion of the volume of the sea, bringing the rise to over 80m. Since the majority of large human cities are situated on coasts, a sea rise of this magnitude would be devastating to human civilisation, no matter how protracted the occurrence.
The United Nations Intergovernmental Panel on Climate Change (IPCC) was established in 1988, following the 1986 Brundtland Report recommendations. Its task is to collate information from a vast group of contributors, mainly scientists, concerning the verification and consequences of global warming, and the consequent climate change.
Despite the almost unanimous support of the findings by the scientific community around the world, policy-makers have failed to act in a way which would seem logical, given the seriousness of the consequences of climate change. This failure has been due to interest groups, mainly fossil fuel companies and similar vested interests, who wish to obfuscate public perceptions, with the intent of delaying any meaningful political action.
One of the parameters commonly requested by the lay public is an estimate of expected sea level rise - a factor seen to have immediate impact on human civilisation. However, there are so many variables involved, it has taken a long time to develop models which may be considered to have any reliability. There remains a broad uncertainty as to how much sea levels may rise. It is unlikely to be linear - a set number of metres per degree of temperature rise - since the rise is due to two chief factors: calorific expansion and the liberation of liquid water from permanent or long-term stores of ice, snow, and permafrost.
The IPCC Fifth Assessment Report (AR5) was published in 2014. One of its summary statements:
Further Summary Statements:
In other words, the world will experience climate change, even if human damage to the biosphere were to cease immediately.
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1832 - 1897
Julius von Sachs was a German botanist who was a pioneer of plant physiology.
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