The relative stability in temperature from 2002 to 2009 is consistent with such an episode.  2010 was also an El Onion year. On the low wing of the oscillation, 2011 as a La Nina year was cooler but it was still the 1 lath warmest year since records began in 1880. Of the 13 warmest years since 1880, 11 were the years from 2001 to 2011. Over the more recent record, 2011 was the warmest La Nina year in the period from 1950 to 2011, and was close to 1997 which was not at the lowest point of the cycle.  Temperature changes vary over the globe. Since 1979, land temperatures have increased about twice as fast as ocean temperatures (0. 5 co per decade against 0. 13 co per decade).  Ocean temperatures increase more slowly than land temperatures because of the larger evaporation.  The northern hemisphere is also naturally warmer than the southern hemisphere mainly because of meridian heat transport in the oceans which has a differential of about 0. 9 pederasts northwards, with an additional contribution from the lobed differences between the polar regions. Since the beginning of industrialization the entrepreneurship temperature difference has increased due to melting of sea ice and snow in the North. 48] Average arctic temperatures have been increasing at almost twice the rate of the rest of the world in the past 100 years, however arctic temperatures are also highly variable. 49] Although more greenhouse gases are emitted in the Northern than Southern Hemisphere this does not contribute to the difference in warming because the major greenhouse gases persist long enough to mix between hemispheres.  The thermal inertia of the oceans and slow responses of other indirect effects mean that climate can take centuries or longer to adjust to changes in forcing.
Climate commitment studies indicate that even if greenhouse gases were stabilized at 2000 levels, a further warming of about 0. 5 co (0. 9 OF) would still occur.  Initial causes of temperature changes (external forcing) Main article: Attribution of recent climate change Greenhouse effect schematic showing energy flows between space, the atmosphere, and earth’s surface. Energy exchanges are expressed in watts per square meter (W/ mm). This graph, known as the Keeling Curve, shows the increase of atmospherically dioxide (ICC) concentrations from 1958-2008.
Monthly Counterarguments display seasonal oscillations in an upward trend; each year’s maximum occurs during thenceforth Hemisphere’s late spring, and declines during its growing season as plants remove some atmospheric ICC. The climate system can respond to changes n external forcing.  External forcing can “push” the climate in the direction of warming or cooling.  Examples of external forcing include changes in atmospheric composition (e. G. , increased concentrations of greenhouse gases), solar luminosity, volcanic eruptions, and variations in Earth’s orbit around the Sun. 55]Orbital cycles vary slowly over tens of thousands of years and at present are in an overall cooling trend which would be expected to lead towards an ice age, but the 20th counterargument’s temperature record shows a sudden rise in global temperatures.  Greenhouse gases Main articles: Greenhouse gas, Greenhouse effect, Irradiative forcing, and Carbon dioxide in Earth’s atmosphere The greenhouse effect is the process by which absorption and emission of infrared radiation by gases in the atmosphere warm a planet’s lower atmosphere and surface.
It was proposed oppose Fourier in 1824, discovered in 1860 by John Tyndale, was first investigated quantitatively by Savant Awareness in 1896, and was developed in the sass through sass by Guy Stewart Calendar.  Bubble diagram showing the share of global cumulative energy-related carbon dioxide emissions for major emitters between 1890-2007. 60] Naturally occurring amounts of greenhouse gases have a mean warming effect of about 33 co(59 [C] Without the earth’s atmosphere the temperature across almost the entire surface of the earth would be below freezing. 62] The major greenhouse gases are water vapor, which causes about 36-70% of the greenhouse effect; carbon dioxide (ICC), which causes 9-26%; methane(CHI), which causes 4-9%; and ozone (03), which causes 3-7%.  Clouds also affect the radiation balance through cloud forcing similar to greenhouse gases. Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, eating to increased irradiative forcing from ICC, methane, troposphere ozone, Cuffs and nitrous oxide.
According to work published in 2007, the concentrations of ICC and methane have increased by 36% and 148% respectively since 1750.  These levels are much higher than at any time during the last 800,000 years, the period for which reliable data has been extracted from ice Less direct geological evidence indicates that ICC values higher than this were last seen about 20 million years ago.  Fossil fuel burning has produced about three-quarters of the increase in ICC from human activity over the past 20 years.
The rest of this increase is caused mostly by changes in land-use, particularly deforestation. Estimates of global ICC emissions in 2011 from fossil fuel combustion, including cement production and gas flaring, was 34. 8 billion tones (9. 5 5 Pig), an increase of 54% above emissions in 1990. Coal burning was responsible for 43% of the total emissions, oil 34%, gas 18%, cement 4. 9% and gas flaring In May 2013, it was reported that readings for ICC taken at the world’s primary benchmark site in Manna Lola surpassed pump.
According to professor Brian Haskins, this is likely the first time ICC levels have been this high for about 4. Million years.  Over the last three decades of the 20th century, gross domestic product per capita and population growth were the main drivers of increases in greenhouse gas emissions.  ICC emissions are continuing to rise due to the burning of fossil fuels and land-use change. :71 Emissions can be attributed to different regions, e. G. , see the figure opposite. Attribution of emissions due to land-use change is a controversial issue. 79]:289 Emissions scenarios, estimates of changes in future emission levels of greenhouse gases, have been projected that depend upon uncertain economic, sociological, technological, ND natural developments.  In most scenarios, emissions continue to rise over the century, while in a few, emissions are reduced.  Fossil fuel reserves are abundant, and will not limit carbon emissions in the 21st century.  Emission scenarios, combined with modeling of the carbon cycle, have been used to produce estimates of how atmospheric concentrations of greenhouse gases might change in the future.
Using the six EPIC SERE “marker” scenarios, models suggest that by the year 2100, the atmospheric concentration of ICC could range between 541 and 970 pump. 85] This is an increase of 90-250% above the concentration in the year 1750. The popular media and the public often confuse global warming with ozone depletion, I. E. , the destruction of stratospheric ozone by chlorofluorocarbons.  not strong. Reduced stratospheric ozone has had a slight cooling influence on surface temperatures, while increased troposphere ozone has had a somewhat larger warming effect. 88] Gases that contribute to the greenhouse effect include: Water vapor. The most abundant greenhouse gas, but importantly, it acts as a feedback to the climate. Water vapor increases as the Earth’s atmosphere warms, but o does the possibility of clouds and precipitation, making these some of the most important feedback mechanisms to the greenhouse effect. Carbon dioxide (ICC). A minor but very important component of the atmosphere, carbon dioxide is released through natural processes such as respiration and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels.
Humans have increased atmospheric ICC concentration by a third since the Industrial Revolution began. This is the most important long-lived “forcing” of climate change. Methane. A hydrocarbon gas produced both through natural sources and human activities, including the decomposition of wastes in landfills, agriculture, and especially rice cultivation, as well as ruminant digestion and manure management associated with domestic livestock. On a molecule-for-molecule basis, methane is a far more active greenhouse gas than carbon dioxide, but also one which is much less abundant in the atmosphere.
Nitrous oxide. A powerful greenhouse gas produced by soil cultivation practices, especially the use of commercial and organic fertilizers, fossil fuel combustion, nitric acid production, and biomass burning. Chlorofluorocarbons (Cuffs). Synthetic compounds of entirely of industrial origin used in a number of applications, but now largely regulated in production and release to the atmosphere by international agreement for their ability to contribute to destruction of the ozone layer. They are also greenhouse gases. On Earth, human activities are changing the natural greenhouse.
Over the last century the burning of fossil fuels like coal and oil has increased the concentration of atmospheric carbon dioxide (ICC). This happens because the coal or oil burning process combines carbon with oxygen in the air to make ICC. To a lesser extent, the clearing of land for agriculture, industry, and other human activities have increased concentrations of greenhouse gases. The consequences of changing the natural atmospheric greenhouse are difficult to predict, but certain effects seem likely: On average, Earth will become warmer.
Some regions may welcome warmer temperatures, but others may not. Warmer conditions will probably lead to more evaporation and precipitation overall, but individual regions will vary, some becoming wetter and others dryer. A stronger greenhouse effect will warm the oceans and partially melt glaciers and there ice, increasing sea level. Ocean water also will expand if it warms, contributing further to sea level rise. Meanwhile, some crops and other plants may respond favorably to increased atmospheric ICC, growing more vigorously and using water more efficiently.
At the same time, higher temperatures and shifting climate patterns may change the areas where crops grow best and affect the makeup of natural plant communities. The major role of water vapor in absorbing thermal radiation is in some respects balanced by the fact that when condensed it causes an lobed effect which reflects bout one third of the incoming sunlight back into space. This effect is enhanced by atmospheric sulfate aerosols and dust, which provide condensation nuclei.
Nearly half the sulfates in the atmosphere originate from sulfur dioxide emissions from power stations and industry, particularly in the northern hemisphere. Volcanoes have contributed substantially to dust and acid aerosol levels high in the atmosphere. The Mount Punctuation eruption in 1991 in the Philippines reduced average temperatures about half a degree C. While at lower levels in the atmosphere sulfate aerosols and just are short-lived, such material in the stratosphere remains for years, increasing the amount of sunlight which is reflected away.
Hence there is, for the time being, a balancing cooling effect on the earth’s surface. In the northern hemisphere the sulfate aerosols are estimated to counter nearly half the heating effect due to anthropogenic greenhouse gases. However, in many countries there are now programs to reduce sulfur dioxide emissions from power stations, as these emissions cause acid rain. Hence this balancing factor will diminish and the rate of temperature increase due to greenhouse gases may consequently increase. Removing the sulfate aerosols is likely to be equivalent to increasing ICC levels by pump, according to a senior UK climate scientist.
Understanding the Effects of Climate Change and Global Warming Realizing that global warming doesn’t only mean higher temperatures Global warming isn’t Just about rising temperatures; it’s about the effects of those higher temperatures: * Stormier storms: Rising sea temperatures release more water vapor into the air above the ocean. When hurricanes form, they pick up this increased vapor, which creates a more intense storm. * Chillier cold: In some rather areas, melting snow and ice cool the sea water that currently offers a moderating effect on those areas. Drier deserts: Arid areas can expect to be drier for longer periods each year, and other areas may become drier. Wading into the effects of global warming on water Changes in temperature affect the planet’s lakes, rivers, and oceans dramatically. Drought conditions, caused primarily by dried-up water sources and dramatically reduced rainfall. The amount of land affected by drought worldwide has doubled in the last 30 years. * Increased flooding due to rising sea levels, unusually heavy rainfall, and rapidly melting snow.