世界气候变化Climate Change(温室效应Green House Effect)英文介绍

into space; the rest is absorbed by Earth’s system 3. Because of greenhouse gases in the atmosphere, only some of the sun’s energy is allowed to escape immediately—instead, the gases stay within the atmosphere, bouncing in all directions 4. The atmosphere is heated up as less and less gases are let out into space and more energy is absorbed by Earth
CO2 emissions Every ton of coal actually releases 2.86 tons of CO2—how is this possible?
Because coal is compressed carbon—when the carbon gets released,
Definitions according to

Global Warming process
1. The sun emits energy towards the Earth 2. The Earth reflects around 30% of the energy back
Process
Causes
What human-related causes are there? Deforestation Agriculture Fossil fuel burning Aerosol gases
Human-Related Causes
Deforestation The cutting of trees decreases the amount of CO2 that can be absorbed by plants for recycling Agriculture (fertilizer and manure) Overeating meat and incorrect diets of livestock create extra manure, releasing larger amounts of methane Fossil fuel burning (Coal, oil, natural gas, etc.) Exhaust from cars, trucks, other vehicles of transportation Power plants burning fossil fuels for electricity Emits CO2 and CO Aerosol gases Comes from spray cans (i.e. bug spray), dust, other particulates Gases block the sun’s light from being absorbed by the surface; instead, the particles absorb the light and keep it in the air (look at prior picture)
Definition
(n.): a change in global climate patterns apparent
from the mid to late 20th century onwards, attributed largely to the increased levels of atmospheric carbon dioxide produced by the use of fossil fuels. It is commonly known as “global warming”
they not only store CO2, but also release oxygen in to the atmosphere Trees hold water in roots; prevent soil erosion; harbor species
When destroyed, trees release stored CO2 into the air;
Fossil Fuel burning
When fossil fuels are burnt, they release CO2—why? Because fossil fuels are animals and plants, which store CO2 in their bodies; if you burn a live tree, it will release CO2 as well Burning fossil fuels for electricity accounts for around 37% of all
deforestation is responsible for about 20% of all CO2 emissions by humans It is estimated that more than 1.5 billion tons of CO2 are released into the atmosphere because of cutting and burning forests every year—burning being a two-fold polluter Over 30 million acres of forest are destroyed every year, mostly to plant crops to feed livestock, building houses, and firewood; about 50% of world’s tropical (i.e. Amazon) forests have been destroyed
it combines with the oxygen to form CO2
Coal is also the most dangerous fuel because it is carbon that is
stored in the ground for millions of years—when we release it, we are adding new carbon In the U.S., just under 50% of electricity comes from coal
Agriculture
In the U.S., 20% of CO2 emissions come from agriculture If we count all the fuel and oil needed to produce pesticides or


to use tractors and machinery, that number jumps to 25-30% of U.S. CO2 emissions The IPCC (Intergovernmental Panel on Climate Change) states that agriculture is responsible for around 12% of all CO2 emissions around the world Clearing forests (deforestation) for farmland Livestock increase methane emissions—account for about 85% of all methane emissions Genetically Modified Organisms (GMOs) are fed to the livestock instead of grass and grain, which disturbs the livestock’s digestive system; therefore, they release more gas

Deforestation
“Clear cutting”: cutting down a forest and removing all plants to
make a certain area “clear” of vegetation Forests are essential for life;
Contr. The most abundant greenhouse gas, but importantly, it acts as a



feedback to the climate. Water vapor increases as greenhouse gases do; therefore, more precipitation leads to even more precipitation and so on. Carbon dioxide (CO2). A minor but the most important component of the atmosphere, carbon dioxide is released through natural processes such as breathing and volcano eruptions and through human activities such as deforestation, land use changes, and burning fossil fuels. Humans have increased atmospheric CO2 concentration by a third since the Industrial Revolution began. Methane. (MH4) A natural and human created hydrocarbon gas cause by the decay of wastes in landfills, agriculture (especially rice cultivation), and manure from livestock. Much less abundant in the atmosphere, but more “powerful” than CO2. Nitrous oxide (N2O). 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 (CFCs). Synthetic compounds of industrial origin used in a number of applications. Emissions are regulated by international organizations because of their contribution to destroying the ozone layer.