File Name: global warming causes and effects .zip
Climate change is a global challenge that has no borders and to combat it requires coordinated work by all countries.
Jump to navigation. And yes, it's really happening. Over the past 50 years, the average global temperature has increased at the fastest rate in recorded history.
Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. Climate change poses significant risks for a wide range of human and natural systems. Although the scientific process is always open to new ideas and results, the fundamental causes and consequences of climate change have been established by many years of scientific research, 1 are supported by many different lines of evidence, and have stood firm in the face of careful examination, repeated testing, and the rigorous evaluation of alternative theories and explanations. This chapter provides a brief overview of some basic facts about the risks posed by climate change see Box 2.
Global warming , the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries.
Increases in greenhouse gases —i. Continued global warming is expected to impact everything from energy use to water availability to crop productivity throughout the world. Poor countries and communities with limited abilities to adapt to these changes are expected to suffer disproportionately. Global warming is already being associated with increases in the incidence of severe and extreme weather, heavy flooding , and wildfires —phenomena that threaten homes, dams, transportation networks, and other facets of human infrastructure.
Temperature increases related to global warming have been the most pronounced at the poles, where they often make the difference between frozen and melted ice. Polar bears rely on small gaps in the ice to hunt their prey. As these gaps widen because of continued melting, prey capture has become more challenging for these animals. In the IPCC reported that the interval between and saw an increase in global average surface temperature of approximately 0. The increase is closer to 1.
A special report produced by the IPCC in honed this estimate further, noting that human beings and human activities have been responsible for a worldwide average temperature increase of between 0.
The predicted rise in temperature was based on a range of possible scenarios that accounted for future greenhouse gas emissions and mitigation severity reduction measures and on uncertainties in the model projections. Some of the main uncertainties include the precise role of feedback processes and the impacts of industrial pollutants known as aerosols , which may offset some warming.
Such damage would include increased extinction of many plant and animal species, shifts in patterns of agriculture , and rising sea levels. By all but a few national governments had begun the process of instituting carbon reduction plans as part of the Paris Agreement , a treaty designed to help countries keep global warming to 1.
Authors of a special report published by the IPCC in noted that should carbon emissions continue at their present rate, the increase in average near-surface air temperatures would reach 1.
Past IPCC assessments reported that the global average sea level rose by some 19—21 cm 7. It also predicted, again depending on a wide range of scenarios, that the global average sea level would rise 26—77 cm The scenarios referred to above depend mainly on future concentrations of certain trace gases, called greenhouse gases , that have been injected into the lower atmosphere in increasing amounts through the burning of fossil fuels for industry, transportation , and residential uses.
In the IPCC reported that concentrations of carbon dioxide, methane, and nitrous oxides in the atmosphere surpassed those found in ice cores dating back , years.
Of all these gases, carbon dioxide is the most important, both for its role in the greenhouse effect and for its role in the human economy. It has been estimated that, at the beginning of the industrial age in the midth century, carbon dioxide concentrations in the atmosphere were roughly parts per million ppm.
By the middle of they had risen to ppm, and, if fossil fuels continue to be burned at current rates, they are projected to reach ppm by the midst century—essentially, a doubling of carbon dioxide concentrations in years.
A vigorous debate is in progress over the extent and seriousness of rising surface temperatures, the effects of past and future warming on human life, and the need for action to reduce future warming and deal with its consequences. This article provides an overview of the scientific background and public policy debate related to the subject of global warming.
It considers the causes of rising near-surface air temperatures, the influencing factors, the process of climate research and forecasting, the possible ecological and social impacts of rising temperatures, and the public policy developments since the midth century.
Global warming Article Media Additional Info. Article Contents. Print print Print. Table Of Contents. While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions. Facebook Twitter. Give Feedback External Websites. Let us know if you have suggestions to improve this article requires login.
External Websites. Articles from Britannica Encyclopedias for elementary and high school students. An overview of the role greenhouse gases play in modifying Earth's climate.
During the second half of the 20th century and early part of the 21st century, global average surface temperature increased and sea level rose. Over the same period, the amount of snow cover in the Northern Hemisphere decreased. Top Questions. Graph of the predicted increase in Earth's average surface temperature according to a series of climate change scenarios that assume different levels of economic development, population growth, and fossil fuel use.
The assumptions made by each scenario are given at the bottom of the graph. Get a Britannica Premium subscription and gain access to exclusive content. Subscribe Now. The greenhouse effect on Earth. Some incoming sunlight is reflected by Earth's atmosphere and surface, but most is absorbed by the surface, which is warmed.
Infrared IR radiation is then emitted from the surface. Some IR radiation escapes to space, but some is absorbed by the atmosphere's greenhouse gases especially water vapour, carbon dioxide, and methane and reradiated in all directions, some to space and some back toward the surface, where it further warms the surface and the lower atmosphere. Load Next Page.
Human action is causing an increase in global temperature. For that reason, the greenhouse effect, far from being our great ally as was the case in the past, is now a risk to our survival. The flooding of coastal cities, the desertification of fertile areas, the melting of glacial masses and the proliferation of devastating hurricanes are just some of the main consequences. Global warming is having a profound impact on the processes of soil degradation and is contributing to the desertification of the most arid areas on the planet. The increase in the global temperature of the planet produces a rise in the level of the sea, which will cause the disappearance of islands and coastal cities. The greenhouse effect is a natural phenomenon and is beneficial for us. Certain gases in the atmosphere retain part of the thermal radiation emitted by the Earth's surface after being heated by the sun, this maintains the planet's temperature at a level suitable for the development of life.
The potential future effects of global climate change include more frequent wildfires, longer periods of drought in some regions and an increase in the number, duration and intensity of tropical storms. Global climate change has already had observable effects on the environment. Glaciers have shrunk, ice on rivers and lakes is breaking up earlier, plant and animal ranges have shifted and trees are flowering sooner. Effects that scientists had predicted in the past would result from global climate change are now occurring: loss of sea ice, accelerated sea level rise and longer, more intense heat waves. Scientists have high confidence that global temperatures will continue to rise for decades to come, largely due to greenhouse gases produced by human activities.
The evidence is clear: the main cause of climate change is burning fossil fuels such as oil, gas, and coal. When burnt, fossil fuels release carbon dioxide into the air, causing the planet to heat up. The climate on Earth has been changing since it formed 4.
Global warming is likely to be the greatest threat of the 21st century.
Global warming , the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries. Increases in greenhouse gases —i. Continued global warming is expected to impact everything from energy use to water availability to crop productivity throughout the world.
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Global warming , the phenomenon of increasing average air temperatures near the surface of Earth over the past one to two centuries.Paige G. 20.03.2021 at 21:58
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This very real threat has dire consequences for our earth and our health. From the causes to prevention, learn the facts you need know.