The difference between the terms “weather” and “climate” is subtle yet important to understanding their respective implications. Simply put, the distinction between the two is time. Weather refers to the behaviors of the Earth’s atmosphere over a short period of time. In the previous Coastal hazards Primers, hurricanes, wind, and winter storms are examples of weather. Climate, however, refers to the long-term behavior of the atmosphere that goes beyond individual events.
According to the IPCC 2007 Fourth Assessment Report, warming of the earth’s climate system is unequivocal.31 Human activities are at least partly responsible by increasing the atmospheric concentration of greenhouse gases from burning fossil fuels and land-use changes, including deforestation:
"There is very high confidence [greater than 9 in 10 chance] that the net effect of human activities since 1750 has been one of warming... Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic GHG [greenhouse gas] concentrations. It is likely [greater than 66% confidence level] that there has been significant anthropogenic warming over the past 50 years averaged over each continent (except Antarctica)."32
Anthropogenic warming of the climate is expected to continue and perhaps accelerate in the 21st century, depending on greenhouse gas (GHG) emissions: "Continued GHG emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely [greater than 90% confidence level] be larger than those observed during the 20th century."33
Trying to understand all of the information provided in the IPCC Fourth Assessment can be a challenge, so a more convenient and streamlined Frequently Asked Questions (FAQ) document has been prepared that explains some of the more common questions around the key concepts and findings.34
What Climate Change Means for Coastal Connecticut
There are many aspects of climate change that could influence the severity of coastal hazards, but the primary concerns are the implications of sea level rise, potential changes in storm activity and the combined effect of the two. In this light, climate change can be viewed as a "coastal hazards multiplier." Rising seas and potential changes in storm activity can make flooding and erosion worse. Consider the following findings from "Confronting Climate Change in the U.S. Northeast: Science, Impacts, and Solutions" (2007):35
- Boston and Atlantic City can expect a coastal flood equivalent to today’s 100-year flood every two to four years on average by mid-century and almost annually by the end of the century.
- New York City is projected to face flooding equivalent to today’s 100-year flood once every decade on average under the IPCC higher-emissions scenario and once every two decades under the IPCC lower-emissions scenario by century’s end.
- Because of the erosive impact of waves, the extent of shoreline retreat and wetland loss is projected to be many times greater than the loss caused by a rise in sea level itself.
For more information on these issues and Connecticut climate change in general, please visit the Connecticut Climate Change Website, specifically the section on adaptation. Adaptation refers to efforts to respond to the impacts resulting from climate change. It requires efforts to assess the impacts Connecticut will face, the risks they will impose, the capacity of the State to adapt, and the strategies that we can use to address these challenges. A result of successful adaptation efforts is an increased resilience of people, communities, the built environment, and natural systems, enabling them to more effectively withstand and rebound from changing climates and extreme weather events.
It is important to note that a focus on adaptation does not mean a lessened focus on mitigation (i.e., efforts to reduce greenhouse gas emissions). According to the IPCC, "adaptation alone is not expected to cope with all the projected effects of climate change, and especially not over the long term as most impacts increase in magnitude."36
Visit our Coastal Hazards Management page for useful ideas for municipal officials and home- or business-owners as well as links to other resources. Additionally, NOAA has provided an online portal for coastal climate change adaptation that provides many useful guides and resources.