In this section, you will learn about the following key mechanisms that change the climate – now and in the past:
- Feedback processes
- Greenhouse effect
- Greenhouse gases (GHG)
- Natural processes
- The sun’s effect on climate
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Throughout our planet’s history, the climate has changed in dramatic ways.
What makes this point in time different from the past is the human influence on this change, and the rate at which this change is occurring.
Scientific evidence shows us that carbon dioxide (CO2) concentrations in the atmosphere have increased substantially since industrialization. The use of fossil fuels has become an increasingly important part of our lives. We rely on fossil fuels for everything from driving our cars, to heating our homes, to producing the products that we have come to rely on in our daily lives. As a result, carbon dioxide concentrations have increased approximately 30% since pre-industrial times. This has resulted in a strengthening of the greenhouse effect, which has played a critical role in warming our planet.
Humans are also causing changes to our planet through other means, such as land use change. Trees, which are a valuable carbon sink, are being cleared at increasing rates to make room for urban development, human settlement and agricultural purposes. By removing these valuable carbon sinks, we are hastening warming even further.
Methane concentration in the atmosphere has increased approximately 150% since pre-industrial times. This increase has also played a role in the warming that we are currently observing. Again, our dependence on fossil fuels, as well as land use changes, has resulted in increasing methane concentrations in our atmosphere. Intensive livestock operations and anaerobic decomposition of organic matter in landfills and elsewhere play an important part in this increase.
We are consumers. The convenient products and services that we have come to expect are causing profound changes to our world. Our lives have become easier since industrialization, but this ease has come at a great cost. Current scientific evidence has shown us the scope of the changes that our activities and lifestyles have caused, as well as what our future could look like should we choose to continue on the same path. Our planet is warning us that it can not support our current way of life.
Knowledge, however, is our greatest defense in light of these changes. By understanding how we fit into the overall climate change equation, we can opt to make changes to the way we live our lives. These changes will help us leave behind a home for future generations of all living things.