The climate of the Earth has changed many times during the history of planet, with occurrences ranging from ice ages to long periods of warmth. In the past, natural factors such as volcanic eruptions, the amount of energy released from the Sun and changes in the orbit of the Earth have affected the climate of the Earth. The climate of the Earth is also influenced by the human activities associated with the Industrial Revolution that began in the late eighteenth century.
The term climate change is often associated with the term global warming. Climate change can be defined as the significant changes in the climate of the Earth, such as precipitation, temperature or wind, which lasts for an extended period of time, e.g. for decades or longer.
Climate change may result from:
- Natural factors, such as slow changes in the orbit of the Earth around the sun or the intensity of the sun changes;
- Natural processes within the climate system, for example changes in ocean circulation;
- Human activities that change the composition of the atmosphere of the Earth, such as through the burning of fossil fuels or through deforestation.
Global warming is a term used to describe the average increase in the temperature of the atmosphere near the surface of the Earth and in the troposphere. These increases in temperature can contribute to changes in global climate patterns. Global warming can occur from a number of causes, both man-made and naturally occurring. Global warming is also commonly associated with the warming that occurs as a result of increased emissions of greenhouse gases from human activities.
The burning of fossil fuels such as coal and oil and deforestation for the past 200 years has caused the concentrations of greenhouse gases to increase significantly in the Earth’s atmosphere. These greenhouse gases prevent heat from escaping from our atmosphere to space, similar to the glass panels of a greenhouse.
Greenhouse gases are necessary to life because they keep the surface of our planet warmer than it otherwise would be. On the other hand, as the concentrations of these greenhouse gases continue to increase in the atmosphere, the temperature of the Earth will climb above past levels.
NASA has reported that global temperatures have increased steadily since the 1970s, and 18 of the 19 hottest years on record, excluding 1998, have occurred since 2001.
Most of the warming in recent decades is due to human activities. Other aspects of the climate are also changing such as sea levels, rainfall patterns as well as snow and ice cover.
Scientists are certain that human activities are changing the composition of the Earth’s atmosphere and the increase in the concentration of greenhouse gases will change the climate of our planet. Unfortunately, scientists are unsure by how much it will change, at what rate it will change, or what the exact effects will be in the long run.
However, plenty of environmental devastation is already being evidenced, and people, plants, and animals will all be affected by climate change. Scientists are working to better understand future climate changes and how the consequences will vary by region and over time.
Effects Due to Climate Change
Scientists have noticed some key changes that are already happening. Observed effects due to climate change include a rise in sea level, changes in the range and distribution of plants and animals, shrinking glaciers, lengthening of growing seasons, trees blooming earlier, ice on rivers and lakes freezing later and breaking up earlier, and thawing of permafrost. Another key issue being studied is how societies and the Earth's environment will adapt to or handle difficult situations with climate change.
Human health can be impacted directly and indirectly by climate change in part through extreme periods of heat and cold, storms, and climate-sensitive diseases such as malaria, and smog episodes.
Smog has been a problem in London since as early as 1306, when Edward I banned coal for a brief time to reduce the amount of smoke being produced. In 1952, smog caused the death of 4,000 people in four days, with a further 8,000 dying as a result of the air pollution problem.
Many cities are thought to be operating in unsafe levels of air pollution, with health risks including asthma, bronchitis, emphysema, and even Alzheimer’s disease.
This article was updated on 12th April, 2019.