GLOBAL WARNING

INTRODUCTION

.

Global warming is a slow steady rise in Earth's surface temperature. Temperatures today are 0.74 °C (1.33 °F) higher than 150 years ago. Many scientists say that in the next 100–200 years, temperatures might be up to 6 °C (11 °F) higher than they were before the effects of global warming were discovered. 

The basic cause seems to be a rise in atmospheric carbon dioxide concentration  when people use fossil fuels like coal and oil, this adds carbon dioxide to the air. When people cut down many trees (deforestation), this means less carbon dioxide is taken out of the atmosphere by those plants.

Future climate change and associated impacts will differ from region to region.  Anticipated effects include increasing global temperatures, rising sea levels, changing precipitation, and expansion of deserts in the subtropics.Warming is expected to be greater over land than over the oceans and greatest in the Arctic, with the continuing retreat of glaciers, permafrost and sea ice. Other likely changes include more frequent extreme weather events such as heat waves, droughts, heavy rainfall with floods and heavy snowfall; ocean acidification; and species extinctions due to shifting temperature regimes. Effects significant to humans include the threat to food security from decreasing crop yields and the abandonment of populated areas due to rising sea levels. Because the climate system has a large "inertia" and greenhouse gases will remain in the atmosphere for a long time, many of these effects will persist for not only decades or centuries, but for tens of thousands of years to come.

GREEN HOUSES

The greenhouse effect is the process by which absorption and emission of infrared radiation by gases in a planet's atmospherewarm its lower atmosphere and surface. On Earth, an atmosphere containing naturally occurring amounts of greenhouse gases causes air temperature near the surface to be about 33 °C (59 °F) warmer than it would be in their absence.^[6[d] Without the Earth's atmosphere, the Earth's average temperature would be well below the freezing temperature of water. The major greenhouse gases are water vapour, which causes about 36–70% of the greenhouse effect; carbon dioxide (CO₂), which causes 9–26%; methane (CH₄), which causes 4–9%; and ozone (O₃), which causes 3–7%.  Clouds also affect the radiation balance through cloud forcings similar to greenhouse gases.

Human activity since the Industrial Revolution has increased the amount of greenhouse gases in the atmosphere, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs and nitrous oxide. 

CAUSES OF GLOBAL WARMING 

Earth's climate has always been in a state of flux, according to data gleaned from the geological record, ice core samples and other sources. However, since the Industrial Revolution began in the late 1700s, the world's climate has been changing in a rapid and unprecedented way. 

The average global temperature has risen 1.4 degrees Fahrenheit (0.8 degrees Celsius) since 1880, according to NASA. Temperatures are projected to rise another 2 degrees to 11.5 degrees F (1.13 degrees to 6.42 degrees C) over the next 100 years, according to the U.S. Environmental Protection Agency (EPA). 

Some have confused global warming as persistent, increasing warmth. While the global temperature is increasing, it may not translate to a higher temperature in an individual location. "Global warming is important because it is so persistent and global in scale, and because it brings more extreme events such as heat waves — not because it makes every place warm all the time. It doesn't do that," said atmospheric scientist Adam Sobel, author of "Storm Surge: Hurricane Sandy, Our Changing Climate, and Extreme Weather of the Past and Future" (HarperWave, 2014). In addition to heat waves, the increase in global temperature is having a massive effect on the environment, such as melting polar ice caps, raising the sea level and fueling dangerous and severe weather patterns. Understanding the causes of global warming is the first step to curbing its effects. 

CAUSES OF GREENHOUSES

The greenhouse effect is the process thanks to which Earth has a higher temperature than it would have without it. The gases that radiate heat also known as greenhouse gases absorb the energy radiated out by the Earth and reflect a part of it back to Earth. Of all the energy that the Earth receives from the Sun, a part of it around 26% is reflected back to space by the atmosphere and clouds. Some part of it is absorbed by the atmosphere, around 19%. The rest hits the ground and heats the surface of the Earth. This absorbed energy is radiated out of the earth in the form of Infrared Waves. These IR waves warm the atmosphere above the Earth. The atmosphere again radiates this energy it received from the Earth both upwards and downwards. The energy sent downwards results in a higher equilibrium temperature that if greenhouse gases were absent. This greenhouse effect is essential to supporting life on Earth. The greenhouse gases responsible for the greenhouse effect are:

.

GREEEN HOUSES EFFECTS

Earth's climate is the result of a balance between the amount of incoming energy from the sun and energy being radiated out into space.

Incoming solar radiation strikes Earth's atmosphere in the form of visible light, plus ultraviolet and infrared radiation (which are invisible to the human eye), according to NASA's Earth Observatory.

Ultraviolet (UV) radiation has a higher energy level than visible light, and infrared (IR) radiation has a lower energy level. Some of the sun's incoming radiation is absorbed by the atmosphere, the oceans and the surface of the Earth.

Much of it, however, is reflected out to space as low-energy infrared radiation. For Earth's temperature to remain stable, the amount of incoming solar radiation should be roughly equal to the amount of IR leaving the atmosphere. According to NASA satellite measurements, the atmosphere radiates thermal IR energy equivalent to 59 percent of the incoming solar energy.

As Earth's atmosphere changes, however, the amount of infrared radiation leaving the atmosphere also changes. Since the Industrial Revolution, the burning of fossil fuels such as coal, oil and gasoline have greatly increased the amount of carbon dioxide (CO2) in the atmosphere, according to NASA's Earth Observatory. Before the industrial revolution, during warm interglacial periods, the concentration of CO2in the atmosphere hovered around 280 parts per million (ppm). A NASA graphshows the rapid increase in this greenhouse gas since then: In 2013, CO2 hit 400 ppm for the first time. In April 2017, the concentration hit 410 ppm for the first time in recorded history. The director of the Scripps Institution of Oceanography CO2 group wrote at the time that levels are expected to hit 450 ppm by 2035, unless greenhouse gas emissions drop significantly.

Along with other gases like methane and nitrous oxide, CO2 acts like a blanket, absorbing infrared radiation and preventing it from leaving the atmosphere. The net effect causes the gradual heating of Earth's atmosphere and surface.

This is called the "greenhouse effect" because a similar process occurs in a greenhouse: Relatively high-energy UV and visible radiation penetrate the glass walls and roof of a greenhouse, but weaker IR can't pass through the glass. The trapped infrared keeps the greenhouse warm, even in the coldest winter weather. 

CONCLUSION 

Both supporters, and anti-supporters of global warming have good views on why, however I believe that global warming is a thing. Using many outside sources, and a video from Stephen Hawking, I feel that global warming is a thing because of the amount of people on Earth.

The more people there are on Earth, the more devices being used, and CO2 being breathed out. The atmosphere cannot recycle the CO2 as fast as it's being produced, therefore trapping in more heat from the sun. Thus making the world hotter. By this happening, the glaciers melt, absorbing more sunlight because the glaciers normally reflect it. When there are no glaciers, the sun will heat up the planet, thus having hydrogen extracted from Earth, causing Earth to be just like Venus.