25-08-2014, 10:32 AM
Global Warming
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What is Global Warming?
Global warming refers to an increase in average global temperature. Natural events and human activities are believed to be contributing to an increase in average global temperature. This is caused primarily by the increase in “greenhouse” gases such as Carbon Dioxide (CO2) and Methane.
A warming planet thus leads to a change in climate which can affect weather in various ways, as discussed further below.
What is Greenhouse Effect?
The term greenhouse is used in conjunction with the phenomenon known as the greenhouse effect.
• Energy from the sun drives the earth’s weather and climate, and heats the earth’s surface;
• In turn, the earth radiates energy back into space;
• Some atmospheric gases (water vapor, carbon dioxide, and other gases) trap some of the
outgoing energy, retaining heat somewhat like the glass panels of a greenhouse;
• These gases are therefore known as greenhouse gases;
Greenhouse gas is natural. What do we do with it?
Many of these greenhouse gases are actually life-enabling, for without them, heat would escape back into space and the Earth’s average temperature would be a lot colder.
However, if the greenhouse effect becomes stronger, then more heat gets trapped than needed, and the Earth might become less habitable for humans, plants and animals.
Carbon dioxide, though not the most potent of greenhouse gases, Human activity has caused an imbalance in the natural cycle of the greenhouse effect and related processes. NASA’s Earth Observatory is worth quoting the effect human activity is having on the natural carbon cycle, for example:
“In addition to the natural fluxes of carbon through the Earth system, anthropogenic (human) activities, particularly fossil fuel burning and deforestation, are also releasing carbon dioxide into the atmosphere.
When we mine coal and extract oil from the Earth’s crust, and then burn these fossil fuels for transportation, heating, cooking, electricity, and manufacturing, we are effectively moving carbon more rapidly into the atmosphere than is being removed naturally through the sedimentation of carbon, ultimately causing atmospheric carbon dioxide concentrations to increase.
Also, by clearing forests to support agriculture, we are transferring carbon from living biomass into the atmosphere (dry wood is about 50 percent carbon).
The result is that humans are adding ever-increasing amounts of extra carbon dioxide into the atmosphere. Due of this, atmospheric carbon dioxide concentrations are higher today than they have been over the last half-million years or longer.”
Greenhouse gases are also essential for our planet; the planet may be able to deal with slightly increased levels of such gases, but too much will affect the health of the whole planet
How much have we increased the Atmosphere's CO2 Concentration?
Human beings have increased the CO2 concentration in the atmosphere by about thirty percent, which is an extremely significant increase, even on inter-glacial timescales. It is believed that human beings are responsible for this because the increase is almost perfectly correlated with increase in fossil fuel combustion, and also due other evidence, such as changes in the ratios of different carbon isotopes in atmospheric CO2 that are consistent with "anthropogenic" (human caused) emissions. The simple fact is that under "business as usual" conditions, we'll soon reach carbon dioxide concentrations that haven't been seen on Earth in the last 50 million years.
Difference in Greenhouse Gas emission around the world
The World Resources Institute highlights the huge rise in greenhouse emissions, as well as the reasons for those emissions. For example:
• In terms of historical emissions, industrialized countries account for roughly 80% of the carbon dioxide buildup in the atmosphere till date. Since 1950, the U.S. has emitted a cumulative total of roughly 50.7 billion tons of carbon, while China (4.6 times more populous) and India (3.5 times more populous) have emitted only 15.7 and 4.2 billion tons respectively (although their numbers will rise).
Brown carbon
An industrial emission of greenhouse gases which affects the climate.
Green carbon
Carbon stored in terrestrial ecosystems e.g. plant biomass, soils, wetlands and pasture and increasingly recognized as a key item for negotiation in the UNFCCC.
Blue carbon
Carbon bound in the world’s oceans. An estimated 55% of all carbon in living organisms is stored in mangroves, marshes, sea grasses, coral reefs and macro-algae.
Black carbon
Formed through incomplete combustion of fuels and may be significantly reduced if clean burning technologies are employed. While those denying climate change are reducing in number and there appears to be more effort to try and tackle the problem, climate scientists are now fearing that
The Arctic plays an incredibly important role in the balance of the earth’s climate. Rapid changes to it can have knock-on effects to the rest of the planet. Some have described, referring to how canary birds used to be taken deep down coal mines. If they die, it implies oxygen levels are low and signals mine workers to get out.
The Arctic plays an incredibly important role in the balance of the earth’s climate. Rapid changes to it can have knock-on effects to the rest of the planet. Some have described, referring to how canary birds used to be taken deep down coal mines. If they die, it implies oxygen levels are low and signals mine workers to get out.
Melting of glaciers
--- Rising global temperatures will speed up the melting of glaciers and ice caps and cause early ice thaw on rivers and lakes.
Widespread vanishing of animal populations --- The list of land species threatened by the effects of global warming is extensive. Amphibians are vanishing at a more alarming rate than any other type of animal. Frogs, toads and salamanders are especially threatened by global warming because they are extremely sensitive to changes in habitat; this includes pollution, climate change, introduction of new species, etc.
Spread of disease
--- An increase in pests and disease is also feared.
A report in the journal Science in June 2002 described the alarming increase in the outbreaks and epidemics of diseases throughout the land and ocean based wildlife due to climate changes.
One of the authors points out that, “Climate change is disrupting natural ecosystems in a way that is making life better for infectious diseases.”
Loss of Plankton due to warming seas
--- The enormous (900 mile long) Aleution island ecosystems of orcas (killer whales), sea lions, sea otters, sea urchins, kelp beds, and fish populations, appears to have collapsed due to loss of plankton, leading to loss of sea lions, leading orcas to eat too many sea otters, leading to urchin explosions, leading to loss of kelp beds and their associated fish populations.
We have a choice
We can act now to reduce our carbon emissions, slow the pace of global warming, and pass on a safer, healthier world to our children. Or we can choose to do nothing, continue pumping massive amounts of carbon into an already overloaded atmosphere, and suffer the increasingly costly consequences. We have the practical solutions and technologies at hand to substantially reduce our emissions and create a clean energy economy