01-02-2019, 03:16 AM
(This post was last modified: 01-02-2019, 03:18 AM by Alan V.)
Climate Change
Climate Change
Climate Change Summarized
Section 1: How we know climate change is happening
Global warming and climate change
Global warming refers to the gradual increase in the global average surface temperature. Since the earth is so vast, the increase of even a few degrees represents an immense amount of heat captured in the atmosphere. Global warming causes climate change, and the more heat captured, the more the climate changes. Climate change affects not only the atmosphere but also the cryosphere (ice), the hydrosphere (the water cycle), and the biosphere (life).
Climate versus weather
Climate is statistically average weather over long periods of time. Weather is often chaotic, which is why it can be predicted with only moderate accuracy in the short term. Climate is not chaotic, which means climate can be predicted with fair accuracy far into the future. It’s like the difference between forecasting if it will rain tomorrow and projecting if it will be hot next summer.
The assumption that climate is equal to weather has caused any number of confusions. No one can tell just by observing local weather events if the global climate is changing or not. Only scientists with a wide range of available information can perform the statistical analyses required to say if the climate is changing and to what degree it is affecting the weather.
Temperatures are rising
The global average surface temperature has risen 1.0̊C (1.8̊F) since 1880. Scientists typically refer to the temperature change caused by global warming as being compared with the preindustrial average. Most of that temperature rise has been within the last 35 years. Every part of the world is affected, though at different rates. In general, temperatures are rising twice as fast at the poles than the average for the rest of the planet. Average temperatures are also rising about twice as fast over the land than over the ocean because of evaporation and the depth of the water. Nevertheless, around 93% of all global warming is absorbed by the oceans. Because so much of the heat of global warming accumulates at the poles and in the oceans, it is not observed except by scientists who monitor temperatures worldwide.
The 2000s have seen more than twice as many record highs as record lows. Heat waves are becoming more frequent and cold snaps are shorter and milder. As of 2010, spring was arriving on average 10 days to 2 weeks earlier than in 1990. Flowers, birds, and other species are moving toward the poles and up mountains to maintain their optimal environments.
Each decade since the 1980s has been warmer than the last. Most of the hottest years on record occurred in the last two decades. The tropics are expanding. Temperatures will continue to rise because the earth is not in thermal equilibrium. The planet is presently warming at a rate of nearly 0.2̊C (0.36̊F) every decade, but may increase that rate of change in the future.
Section 1: How we know climate change is happening
Global warming and climate change
Global warming refers to the gradual increase in the global average surface temperature. Since the earth is so vast, the increase of even a few degrees represents an immense amount of heat captured in the atmosphere. Global warming causes climate change, and the more heat captured, the more the climate changes. Climate change affects not only the atmosphere but also the cryosphere (ice), the hydrosphere (the water cycle), and the biosphere (life).
Climate versus weather
Climate is statistically average weather over long periods of time. Weather is often chaotic, which is why it can be predicted with only moderate accuracy in the short term. Climate is not chaotic, which means climate can be predicted with fair accuracy far into the future. It’s like the difference between forecasting if it will rain tomorrow and projecting if it will be hot next summer.
The assumption that climate is equal to weather has caused any number of confusions. No one can tell just by observing local weather events if the global climate is changing or not. Only scientists with a wide range of available information can perform the statistical analyses required to say if the climate is changing and to what degree it is affecting the weather.
Temperatures are rising
The global average surface temperature has risen 1.0̊C (1.8̊F) since 1880. Scientists typically refer to the temperature change caused by global warming as being compared with the preindustrial average. Most of that temperature rise has been within the last 35 years. Every part of the world is affected, though at different rates. In general, temperatures are rising twice as fast at the poles than the average for the rest of the planet. Average temperatures are also rising about twice as fast over the land than over the ocean because of evaporation and the depth of the water. Nevertheless, around 93% of all global warming is absorbed by the oceans. Because so much of the heat of global warming accumulates at the poles and in the oceans, it is not observed except by scientists who monitor temperatures worldwide.
The 2000s have seen more than twice as many record highs as record lows. Heat waves are becoming more frequent and cold snaps are shorter and milder. As of 2010, spring was arriving on average 10 days to 2 weeks earlier than in 1990. Flowers, birds, and other species are moving toward the poles and up mountains to maintain their optimal environments.
Each decade since the 1980s has been warmer than the last. Most of the hottest years on record occurred in the last two decades. The tropics are expanding. Temperatures will continue to rise because the earth is not in thermal equilibrium. The planet is presently warming at a rate of nearly 0.2̊C (0.36̊F) every decade, but may increase that rate of change in the future.
