Global Warming
Global warming is the increase in the
average temperature of the Earth's near-surface air and oceans in recent
decades and its projected continuation. The global average air temperature near
the Earth's surface raised 0.74 ± 0.18°C during the last 100 years. The delay
in reaching equilibrium is a result of the large heat capacity of the oceans.
Increasing global temperatures will cause sea level to rise, and is expected to
increase the intensity of extreme weather events and to change the amount and
pattern of precipitation.
Other effects of global warming include
changes in agricultural yields, trade routes, glacier retreat, species
extinctions and increases in the ranges of disease vectors. Remaining
scientific uncertainties include the amount of warming expected in the future,
and how warming and related changes will vary from region to region around the
globe. There is ongoing political and public debate worldwide regarding what,
if any, action should be taken to reduce or reverse future warming or to adapt
to its expected consequences.
Most national governments have signed and
ratified the Kyoto Protocol, aimed at reducing greenhouse gas emissions. The
term "global warming" is a specific example of the broader term
climate change, which can also refer to global cooling. In common usage, the
term refers to recent warming and implies a human influence. The detailed
causes of the recent warming remain an active field of research, but the
scientific consensus identifies elevated levels of greenhouse gases due to
human activity as the main influence.
This attribution is clearest for the most
recent 50 years, for which the most detailed data are available. None of the
effects of forcing are instantaneous. Climatic studies indicate that even if
greenhouse gases were stabilized at 2000 levels, a further warming of about
0.5°C would still occur. The effects of forcing agents on the climate are
complicated by various feedback processes. Since water vapor itself acts as a
greenhouse gas, this cause still more warming; the warming causes more water
vapor to be evaporated, and so forth until a new dynamic equilibrium
concentration of water vapor is reached with a much larger greenhouse effect
than that due to CO, alone
Changes in the amount and pattern of
precipitation may result in flooding and drought. There may also be changes in
the frequency and intensity of extreme warming like changes in rainfall
patterns, increased intensity and frequency of extreme weather events, are
being attributed in part to global warming. While changes are expected for
overall patterns, intensity, and frequencies, it is difficult to attribute
specific events to global warming.
Other expected effects include water
scarcity in some regions and increased precipitation in others, changes in
mountain snow pack, and adverse health effects from warmer temperatures.
Increasing deaths, displacements, and economic losses projected due to extreme
weather attributed to global warming may be exacerbated by growing population
densities in affected areas. One study predicts 18% to 35% animal and plant
species would be extinct by 2050, based on future climate projections however,
few mechanistic studies have documented extinctions due to recent climate
change.
It is for us to now take extreme measures
to protect nature, if we have to ensure our future generations live a good and
safe life. Avoiding pollution increment and carbon dioxide emissions can help
in the cause. We must all work together for a better world to stay in.