Read the
text and do the exercises.
Global
problems are those which affect not only one individual but the whole mankind.
They can’t be solved in one day and require organized efforts from the world
community. If people leave these problems unsettled, it may lead to serious
consequences in the future.
Global
warming is considered to be one of the most dangerous threats that our culture
has ever faced. The effects of global warming include more frequent extreme
weather phenomena such as heat waves, droughts, wildfires, floods, heavy
snowfalls and as a result people will experience water shortages, crop failures
and so on.
In 2013,
the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report
concluded, “It is extremely likely that human influence has been the dominant
cause of the observed warming since the mid-20th century.” The largest human
influence has been the emission of greenhouse gases such as carbon monoxide,
carbon dioxide, methane and nitrous oxide. If a planet's atmosphere contains
radiatively active gases, so called greenhouse gases, they will radiate energy
in all directions. Part of this radiation is directed towards the surface,
warming it. The intensity of the downward radiation – that is, the strength of
the greenhouse effect – will depend on the atmosphere's temperature and on the
amount of greenhouse gases that the atmosphere contains.
Earth’s
natural greenhouse effect is critical to supporting life. Human activities,
mainly the burning of fossil fuels and clearing of forests, have strengthened
the greenhouse effect and caused global warming. Climate model projections
summarized in the report indicated that during the 21st century, the global
surface temperature is likely to rise a further 0.3 to 1.7C to 2.6 to 4.8C
depending on the rate greenhouse gas emissions and on climate feedback effect.
Because the
climate system has a large “inertia” and greenhouse gases will remain in the
atmosphere for a long time, climatic changes and their effects will continue to
become more pronounced for many centuries even if further increases to
greenhouse gases stop.
Possible societal responses to global warming
include mitigation by emissions reduction, adaptation to its effects, and
possible future climate engineering.