Question

write a brief upon global warming (10 mark question) ​

Answer 1

This graph illustrates the change in global surface temperature relative to 1951-1980 average temperatures.

This graph illustrates the change in global surface temperature relative to 1951-1980 average temperatures (Source: NASA's Goddard Institute for Space Studies). Learn more about global surface temperature here. Credit: NASA/JPL-Caltech

Global warming is the long-term heating of Earth’s climate system observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth’s atmosphere. The term is frequently used interchangeably with the term climate change, though the latter refers to both human- and naturally produced warming and the effects it has on our planet. It is most commonly measured as the average increase in Earth’s global surface temperature.

Since the pre-industrial period, human activities are estimated to have increased Earth’s global average temperature by about 1 degree Celsius (1.8 degrees Fahrenheit), a number that is currently increasing by 0.2 degrees Celsius (0.36 degrees Fahrenheit) per decade. Most of the current warming trend is extremely likely (greater than 95 percent probability) the result of human activity since the 1950s and is proceeding at an unprecedented rate over decades to millennia.

Answer 2

Explanation:

Global warming is the temperature of Earth's surface, oceans and atmosphere going up over tens to thousands of years.[1] Average temperatures today are about 1 °C (1.8 °F) higher than before people started burning a lot of coal around 1750.[2] But in some parts of the world it is less than this and some more. Most scientists say that by the year 2100 temperatures will be 2 °C (3.6 °F) to 4 °C (7.2 °F) higher than they were before 1750.[3] The changes people can see most easily because of this increase in temperature is the melting of ice caps all around the world. Sea level is rising for two reasons. One reason is because of ice on the land, like Greenland, melting into the sea. The other reason is because of water getting bigger when it gets warmer. Many cities will be partly flooded by the ocean in the 21st century.

Global warming is mostly because of people burning things, like gasoline to make cars go and natural gas to keep houses warm. But the heat from the burning itself only makes the world a tiny bit warmer: it is the carbon dioxide from the burning which is the biggest part of the problem. Among the greenhouse gases, the increase of carbon dioxide in the atmosphere is the main cause of global warming, as predicted by Svante Arrhenius a hundred years ago, confirming the work of Joseph Fourier more than 200 years ago. When people burn fossil fuels like coal, oil and natural gas this adds carbon dioxide into the air.[4] This is because fossil fuels contain lots of carbon and burning means joining most of the atoms in the fuel with oxygen. When people cut down many trees (deforestation), this means less carbon dioxide is taken out of the atmosphere by those plants.