Earths greenhouse effect
is a natural phenomenon that helps
regulate the temperature of our planet. The sun heats the Earth
and some of this heat, rather than escaping back to space
is trapped in the atmosphere by clouds and greenhouse gases, such as
water vapor and carbon dioxide.
If all of these greenhouse gases were to suddenly disappear, our
planet would be about 60 degrees F colder and uninhabitable.
It is unlikely that our Global Warming acceleration is the result of natural
variability alone.
Human activities are at least partially responsible.
Many greenhouse gases occur naturally, but human activities are adding
gases daily to the natural mix at an unprecedented rate.
Water vapor is the abundant greenhouse gas, it occurs naturally and makes
up about two thirds of the natural greenhouse effect.
Fuel burning and other human activities are adding large amounts
of greenhouse gases to the atmosphere.. the most important ones being carbon
dioxide, methane, and nitrous oxide.
Because human emissions of co2 and other greenhouse gases continue to
climb, and because they do remain in the atmosphere for decades to centuries
depending on the type of gas, we're committing our species to
an increasing warmer climate in the future.
The IPCC projects an average global temperature
increase of 2 to 6 degree by 2100 and an unknown greater warming effect thereafter.
Temperature in some parts of the globe like the polar regions are expected to rise
even faster.
Even the low end of the IPCCs projected range represents a rate of climate
change unprecedented in the past 10,000 years.
Our health, agriculture, water resources, forests, wildlife and
coastal areas are vulnerable to global warming and the climatic changes
it will bring
Climate change is likely to have wide ranging and mostly adverse impacts
on human health, with significant loss of life.
A few degrees of warming increases the chances of frequent and severe heat
waves, which can cause more heat related death and illness.
Greater heat can also mean worsened air pollution, as well as
damaged crops and depleted water resources.
Warming is likely to allow tropical diseases, such as malaria, to spread northward in some areas of the world
and It will also intensify the Earth's
hydrological cycle.
This means that both evaporation and precipitation will increase. Some areas will receive more rain, while other areas will be drier.
Warming will cause glaciers at both North and South poles to melt and
our oceans to expand.
The IPCC projects that sea level will rise one half foot to three feet over
the next century.
This threatens and puts at risk.. most low-lying coastal areas.
Scientists are also concerned that global warming may lead to more
intense storms.
Global Temperatures During The Last Ice Age.. About 20,000 Years
Ago
Were Only 9 Degree F Cooler Than Global Temperatures Today
But that was enough to allow
massive ice sheets from the polar cap to reach as far south as the Great Lakes and
New York City.
The warming that humans are causing will change earths climate in the
opposite direction, but tens or possibly a hundred times faster than natural
rates of climate change.
Warming of just a few degrees would lead to more frequent droughts and heat
waves, cause greater rainfall and possibly change the strength of
storms.
It is possible that some areas could benefit from warming even as other
areas were harmed.
