29.2
Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global te…
The earth has undergone period of warming and cooling throughout its history. However, for the last few centuries, there has been a drastic increase in global temperatures, outside of the earth's cyclic norms. Warming occurs when atmospheric greenhouse gasses, like carbon dioxide become trapped between the earth and the ozone layer. Carbon dioxide can absorb solar energy of long infrared wavelengths, preventing it from traveling back into outer space, thus increasing atmospheric temperatures.
Although this is a natural process called the greenhouse effect the sharp increase in the amount of carbon dioxide present in the earth's atmosphere caused by the burning of coal and petroleum, is not. The results of this temperature increase can be see around the globe.
For example, in the Arctic, polar ice caps are melting resulting in sea level rise and island submersion. This not only threatens coastal cities, but also can increase the occurrence of extreme meteorological events, like droughts, hurricanes, and severe storms.
Also migration and breeding patterns of many animals are occurring earlier in the year than they did decades ago and the size of species distributions are decreasing.
As global warming becomes recognized by more skeptics, the increase in environmentally friendly practices by industries may provide opportunities to reverse human impact and help to avoid severe consequences of global climate change.
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Q1: How does the greenhouse effect trap heat in Earth's atmosphere?
Atmospheric greenhouse gases like carbon dioxide absorb solar energy of long infrared wavelengths, preventing it from traveling back into outer space. This natural process increases atmospheric temperatures. However, the sharp increase in carbon dioxide from burning coal and petroleum is causing drastic temperature rises outside Earth's cyclic norms.
Q2: What evidence shows that current global warming differs from past climate cycles?
Throughout Earth's 4.5 billion year history, natural warming and cooling cycles occurred due to variations in Earth's orbit affecting solar radiation. However, current temperature increases are well outside these cyclic norms. Paleoclimatology, the study of ancient climate conditions, provides compelling evidence by comparing recent conditions with past patterns over the last 650,000 years.
Q3: How do ice cores reveal information about Earth's ancient climate?
Ice core samples from glaciers and polar ice sheets contain seasonal layers and trapped materials like air bubbles and oxygen-hydrogen isotope ratios. Researchers analyze these properties to reconstruct ancient climate conditions. The lowest layers are oldest, allowing scientists to establish a chronology and track climate changes over hundreds of thousands of years.
Q4: What are the observable impacts of global warming on polar regions and sea levels?
In the Arctic, polar ice caps are melting, resulting in sea level rise and island submersion. This threatens coastal cities and increases extreme meteorological events like droughts, hurricanes, and severe storms. These physical changes demonstrate the real-world consequences of global climate change on ecosystems and human populations.
Q5: How is global warming affecting animal behavior and population distribution?
Migration and breeding patterns of many animals are occurring earlier in the year than they did decades ago. Additionally, the size of species distributions is decreasing as habitats change. These shifts in animal behavior and range represent significant ecological responses to rising global temperatures and changing environmental conditions.
Q6: How can dendroclimatology help scientists understand past climate patterns?
Dendroclimatology examines annual tree rings to reconstruct past climate conditions. Tree rings are wider under favorable conditions and narrower during harsh times. By matching rings from sample to sample, scientists can accurately date and create high-resolution climate records for specific geographic locations, providing valuable climate proxy data.
Q7: What role can environmentally friendly practices play in addressing global climate change?
As global warming becomes recognized by more skeptics, increased environmentally friendly practices by industries may provide opportunities to reverse human impact and help avoid severe consequences of global climate change. These practices represent a pathway toward sustainable development and management of ecosystems for future generations.