Global Warming: A Threat To The World
                     GLOBAL WARMING: 
A THREAT TO THE 
WORLD
What is Global 
Warming?
Global warming is the long-term heating of 
Earth’s climate system observed since the pre-
industrial period (between 1850 and 1900) due 
to human activities, primarily fossil fuel burning, 
which increases heat-trapping greenhouse gas 
levels in Earth’s atmosphere.
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Source: climate.nasa.gov
Climate change
The term is frequently used interchangeably 
with the term climate change, though the latter 
refers to both human- and naturally produced 
warming and the effects it has on our planet. It 
is most commonly measured as the average 
increase in Earth’s global surface temperature.
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Source: climate.nasa.gov
How the 
greenhouse effect 
plays a role?
The main driver of today's warming is the 
combustion of fossil fuels. These hydrocarbons 
heat up the planet via the greenhouse effect, 
which is caused by the interaction between 
Earth's atmosphere and incoming radiation from 
the sun. 
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Source: www.livescience.com
Effects of global warming
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Melting ice
Perhaps the most visible effect of climate 
change so far is the melting of glaciers and sea 
ice. The ice sheets have been retreating since 
the end of the last ice age, about 11,700 years 
ago, but the last century's warming has 
hastened their demise. 
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Source: www.livescience.com
Heating up
Global warming will change things between the 
poles, too. Many already-dry areas are expected 
to get even drier as the world warms. 
The southwest and central plains of the United 
States, for example, are expected to experience 
decades-long "megadroughts" harsher than 
anything else in human memory.
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Source: www.livescience.com
Extreme 
weather
Another impact of global warming: extreme 
weather. Hurricanes and typhoons are expected 
to become more intense as the planet warms. 
Hotter oceans evaporate more moisture, which 
is the engine that drives these storms. 
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Source: www.livescience.com
Ocean 
disruption
Some of the most immediate impacts of global 
warming are beneath the waves. Oceans act as 
carbon sinks, which means they absorb 
dissolved carbon dioxide. That's not a bad thing 
for the atmosphere, but it isn't great for the 
marine ecosystem.
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Source: www.livescience.com
Health Effects
While health has always been effected by 
climate and weather, it is the change in climate 
and climate variability, particularly changes in 
weather extremes, that is a significant threat to 
human health.
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Source: www.healthaffairs.org
Drought And 
Fires
Heat, stagnant heat, and drought increase the 
prevalence, intensity and duration of wild fires 
particularly in the US West. The Southwest has 
experienced the most persistent droughts since 
record keeping began in 1895. 
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Source: www.healthaffairs.org