What Caused Antarcticaã¢â‚¬â„¢s Climate to Change From a More Temperate Climate to Its Current Climate?

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In Brief:

Human activities (primarily the burning of fossil fuels) have fundamentally increased the concentration of greenhouse gases in Earth's atmosphere, warming the planet. Natural drivers, without man intervention, would push our planet toward a cooling menses.

Scientists aspect the global warming trend observed since the mid-xx^th century to the human being expansion of the "greenhouse effect" ¹ — warming that results when the atmosphere traps rut radiating from Earth toward space.

Certain gases in the atmosphere block heat from escaping. Long-lived gases that remain semi-permanently in the atmosphere and exercise not respond physically or chemically to changes in temperature are described equally "forcing" climate alter. Gases, such as water vapor, which respond physically or chemically to changes in temperature are seen as "feedbacks."

Gases that contribute to the greenhouse event include:

• Water vapor. The well-nigh abundant greenhouse gas, only importantly, it acts every bit a feedback to the climate. Water vapor increases as the World's atmosphere warms, simply so does the possibility of clouds and precipitation, making these some of the nigh important feedback mechanisms to the greenhouse effect.

• Carbon dioxide (CO₂). A minor but very of import component of the temper, carbon dioxide is released through natural processes such equally respiration and volcano eruptions and through human activities such as deforestation, country utilise changes, and called-for fossil fuels. Humans have increased atmospheric CO₂ concentration by 48% since the Industrial Revolution began. This is the near 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 specially rice cultivation, likewise as ruminant digestion and manure management associated with domestic livestock. On a molecule-for-molecule basis, methyl hydride is a far more active greenhouse gas than carbon dioxide, merely also ane which is much less abundant in the temper.

• Nitrous oxide. A powerful greenhouse gas produced by soil cultivation practices, particularly the use of commercial and organic fertilizers, fossil fuel combustion, nitric acid product, and biomass burning.

• Chlorofluorocarbons (CFCs). Synthetic compounds entirely of industrial origin used in a number of applications, only now largely regulated in product and release to the temper by international agreement for their ability to contribute to destruction of the ozone layer. They are also greenhouse gases.

Not enough greenhouse result: The planet Mars has a very thin atmosphere, most all carbon dioxide. Because of the low atmospheric pressure, and with picayune to no methane or water vapor to reinforce the weak greenhouse effect, Mars has a largely frozen surface that shows no evidence of life.

Too much greenhouse effect: The temper of Venus, like Mars, is nearly all carbon dioxide. But Venus has most 154,000 times as much carbon dioxide in its atmosphere as Earth (and about 19,000 times as much every bit Mars does), producing a delinquent greenhouse effect and a surface temperature hot enough to melt lead.

On Globe, 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 (CO_two). This happens because the coal or oil burning procedure combines carbon with oxygen in the air to make CO_ii. To a bottom extent, the clearing of country for agriculture, industry, and other human activities has increased concentrations of greenhouse gases.

The consequences of changing the natural atmospheric greenhouse are difficult to predict, but some effects seem likely:

• On average, Earth will become warmer. Some regions may welcome warmer temperatures, simply others may not.

• Warmer conditions will probably pb to more evaporation and atmospheric precipitation overall, but individual regions will vary, some becoming wetter and others dryer.

• A stronger greenhouse outcome will warm the ocean and partially melt glaciers and ice sheets, increasing sea level. Ocean water besides will expand if it warms, contributing further to body of water level rise.

• Exterior of a greenhouse, higher atmospheric carbon dioxide (CO₂) levels can accept both positive and negative effects on ingather yields. Some laboratory experiments suggest that elevated CO₂ levels tin increment found growth. All the same, other factors, such equally changing temperatures, ozone, and water and nutrient constraints, may more than counteract whatsoever potential increase in yield. If optimal temperature ranges for some crops are exceeded, earlier possible gains in yield may be reduced or reversed altogether.

  Climate extremes, such equally droughts, floods and extreme temperatures, tin can lead to crop losses and threaten the livelihoods of agricultural producers and the food security of communities worldwide. Depending on the crop and ecosystem, weeds, pests, and fungi can also thrive under warmer temperatures, wetter climates, and increased CO₂ levels, and climatic change will likely increase weeds and pests.

  Finally, although rising CO_two tin can stimulate plant growth, research has shown that information technology can also reduce the nutritional value of most nutrient crops by reducing the concentrations of protein and essential minerals in most plant species. Climate change can cause new patterns of pests and diseases to emerge, affecting plants, animals and humans, and posing new risks for nutrient security, food safe and man health. ²

The Function of Human Activity

In its Fifth Assessment Report, the Intergovernmental Panel on Climatic change, a group of 1,300 independent scientific experts from countries all over the world under the auspices of the United Nations, concluded there's a more than 95 percent probability that human being activities over the past 50 years take warmed our planet.

The industrial activities that our modernistic culture depends upon have raised atmospheric carbon dioxide levels from 280 parts per meg to about 417 parts per one thousand thousand in the last 151 years. The panel also concluded there'south a better than 95 percent probability that human being-produced greenhouse gases such equally carbon dioxide, methane and nitrous oxide take caused much of the observed increase in Earth's temperatures over the past 50-plus years.

The panel's full Summary for Policymakers report is online at https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_summary-for-policymakers.pdf.

Solar Irradiance

The to a higher place graph compares global surface temperature changes (crimson line) and the Sun'southward energy that Globe receives (yellow line) in watts (units of energy) per square meter since 1880. The lighter/thinner lines evidence the yearly levels while the heavier/thicker lines evidence the eleven-twelvemonth average trends. Xi-year averages are used to reduce the yr-to-yr natural noise in the data, making the underlying trends more obvious.

The corporeality of solar energy that Globe receives has followed the Sun's natural 11-yr cycle of small ups and downs with no internet increase since the 1950s. Over the same period, global temperature has risen markedly. It is therefore extremely unlikely that the Sunday has caused the observed global temperature warming trend over the past half-century. Credit: NASA/JPL-Caltech

Information technology's reasonable to presume that changes in the Sun's energy output would cause the climate to change, since the Dominicus is the fundamental source of energy that drives our climate organisation.

Indeed, studies prove that solar variability has played a role in past climate changes. For example, a subtract in solar activity coupled with an increase in volcanic activity is idea to have helped trigger the Lilliputian Ice Age between approximately 1650 and 1850, when Greenland cooled from 1410 to the 1720s and glaciers advanced in the Alps.

But several lines of show show that current global warming cannot be explained by changes in energy from the Sun:

• Since 1750, the average amount of energy coming from the Sun either remained constant or increased slightly.

• If the warming were caused by a more active Sun, and so scientists would wait to see warmer temperatures in all layers of the atmosphere. Instead, they accept observed a cooling in the upper atmosphere, and a warming at the surface and in the lower parts of the atmosphere. That's considering greenhouse gases are trapping rut in the lower atmosphere.

• Climate models that include solar irradiance changes tin't reproduce the observed temperature trend over the by century or more than without including a rising in greenhouse gases.

References

1. IPCC Fifth Assessment Report, 2014

   U.s. Global Change Enquiry Programme, "Global Climate Alter Impacts in the The states," Cambridge University Press, 2009

   Naomi Oreskes, "The Scientific Consensus on Climate Modify," Scientific discipline 3 December 2004: Vol. 306 no. 5702 p. 1686 DOI: 10.1126/scientific discipline.1103618

2. U.S. Environmental Protection Agency: "Climate Impacts on Agronomics and Food Supply"

3. Mike Lockwood, "Solar Change and Climate: an update in the low-cal of the electric current exceptional solar minimum," Proceedings of the Regal Lodge A, two December 2009, doi x.1098/rspa.2009.0519;

   Judith Lean, "Cycles and trends in solar irradiance and climate," Wiley Interdisciplinary Reviews: Climatic change, vol. one, Jan/Feb 2010, 111-122.

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Source: https://climate.nasa.gov/causes/

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