Global Warming Causes
Global warming
is primarily a problem of too much carbon dioxide (CO2) in the atmosphere—which
acts as a blanket, trapping heat and warming the planet. As we burn fossil
fuels like coal, oil and natural gas for energy or cut down and burn forests to
create pastures and plantations, carbon accumulates and overloads our
atmosphere. Certain waste management and agricultural practices aggravate the
problem by releasing other potent global warming gases, such as methane and
nitrous oxide. See the pie chart for a breakdown of heat-trapping global
warming emissions by economic sector.
Global Warming Is Urgent and Can Be Addressed
CO2 survives
in the atmosphere for a long time—up to many centuries—so its heat-trapping
effects are compounded over time. Of the many heat-trapping gases, CO2 puts us
at the greatest risk of irreversible changes if it continues to accumulate
unabated in the atmosphere—as it is likely to do if the global economy remains
dependent on fossil fuels for its energy needs. To put this in perspective, the
carbon we put in the atmosphere today will literally determine not only our
climate future but that of future generations as well.
Substantial
scientific evidence indicates that an increase in the global average
temperature of more than 3.6 degrees Fahrenheit (°F) (or 2 degrees Celsius
[°C]) above pre-industrial levels poses severe risks to natural systems and to
human health and well-being. The good news is that, because we as humans caused
global warming, we can also do something about it. To avoid this level of
warming, large emitters such as the United States need to greatly reduce
heat-trapping gas emissions by mid century. Delay in taking such action means
the prospect of much steeper cuts later if there is any hope of staying below
the 3.6°F (2°C) temperature goal. Delayed action is also likely to make it more
difficult and costly to not only make these reductions, but also address the
climate consequences that occur in the meantime.
The Consequences of a Warming World
Over the last
century, global average temperature has increased by more than 1°F (0.7°C). The
2001-2010 decade is the warmest since 1880—the earliest year for which
comprehensive global temperature records were available. In fact, nine of the
warmest years on record have occurred in just the last 10 years. This warming
has been accompanied by a decrease in very cold days and nights and an increase
in extremely hot days and warm nights. The continental United States, for
example, has seen record daily highs twice as often as record daily lows from
2000 to 2009. While the record shows that some parts of the world are warming
faster than others, the long-term global upward trend is unambiguous.
Of course,
land and ocean temperature is only one way to measure the effects of climate
change. A warming world also has the potential to change rainfall and snow
patterns, increase droughts and severe storms, reduce lake ice cover, melt
glaciers, increase sea levels, and change plant and animal behavior.
Regional Actions Add Up to Global Solutions
We encourage
you to visit the solutions section of this web feature to find out how you can
take action to slow the pace of climate change and help minimize the harmful
consequences described in the hot spots!
Any action to
reduce or eliminate the release of heat-trapping gases to the atmosphere helps
slow the rate of warming and, likely, the pace and severity of change at any
given hot spot. Local sources of carbon emissions vary from region to region,
suggesting that solutions are often decided at the community level. The Climate
Hot Map points to regional examples of climate-friendly energy, transportation,
or adaptation choices. Some regions, however, must rely upon global solutions
such as international agreements to reduce the carbon overload in the
atmosphere that threatens them. Small islands, for example, are a paltry source
of carbon emissions and yet are disproportionately affected by the consequences
of global carbon overload as accelerated sea level rise threatens the very
existence of low-lying islands.
Individual,
regional, and national actions can all add up to global solutions, slowing and
eventually halting the upward climb of CO2 Concentrations
in the atmosphere.
Tidak ada komentar:
Posting Komentar