What You Should Know

The difference between weather and climate is a measure of time. EPA's climate change website distinguishes weather from climate this way:

Weather is the state of the atmosphere at any given time and place. Most of the weather that affects people, agriculture, and ecosystems takes place in the lower layer of the atmosphere. Familiar aspects of weather include temperature, precipitation, clouds, and wind that people experience throughout the course of a day. Severe weather conditions include hurricanes, tornadoes, blizzards, and droughts.

Climate is the long-term average of the weather in a given place. While the weather can change in minutes or hours, a change in climate is something that develops over longer periods of decades to centuries. Climate is defined not only by average temperature and precipitation but also by the type, frequency, duration, and intensity of weather events such as heat waves, cold spells, storms, floods, and droughts.

source: EPA Climate Change website, 2015

see full image in NAP gallery

Yes. The globally averaged combined land and ocean surface temperature data, show a warming of 0.85 C (1.4F) since 1880, when the first accurate measurements of global average land and ocean temperature were available (IPCC synthesis report).

In addition, the 10 warmest years, with the exception of 1998, have occurred since 2000 (NASA 2015 press release). The year 2014 ranks as Earth’s warmest since 1880, according to two separate analyses by NASA and the National Oceanic and Atmospheric Administration (NOAA) scientists. The best estimate is that the global average temperature will warm a further 4.7 t0 8.6F by the end of the 21st century, but the range, of projected further increases, according to the The Intergovernmental Panel on Climate Change, is between 2.0°F and  11.5°F by the end of the 21st century. The high amount of variability in this estimate depends in part on what models are used and the uncertainty associated with those models, but is largely dependent on what actions are taken to mitigate climate change and how quickly they are implemented.

The full graphic is at Evidence and Causes, 18.

The region’s temperature has been increasing as well.

Temperature in Long Island Sound is increasing at a rate of about about 1.8°F (1°C) per century. Scientists use locations that have long-term winter temperature readings across the Sound to make this assessment. That’s because winter temperatures of coastal waters throughout Long Island Sound and the Southern New England Region are relatively consistent from day to day and place to place. During the summer, surface water temperatures can change substantially depending on the time of day of the measurement, the current weather, and the location of the sample (near shore vs. offshore).  Across the Sound, while temperatures vary from location to location and year to year, the overall pattern of rising temperatures was similar across the Sound. The trend is shown in Long Island Sound Study’s climate change indicators’ presentation.

see full image in NAS gallery

Since the 1950s, the dominant cause of warming is extremely likely to be caused by human impacts such as the increase in greenhouse gas emissions. (IPCC synthesis report)

While natural causes such as shifts in El Nino and the North Atlantic Oscillation (NAO) can alter temperatures and precipitation patterns, natural causes alone are inadequate to explain recent observed changes in climate, (source:  National Academy of Sciences, Evidence and Causes, p. 5).  A majority of scientists believe that warming temperatures in recent decades are the result of an increase in gases from the burning of fossil fuels, leading to an increase in the “greenhouse effect.” While greenhouse gases are necessary to trap some of the sun’s energy and keep the surface of the planet warm , since the Industrial Revolution began (1800), the concentrations of carbon dioxide, one of the major greenhouse gases, have increased by 40 percent. This buildup of carbon dioxide, combined with increases in other greenhouse gasses such as nitrous oxides (from automobile and power plant exhaust) and methane, causes an increase in the percentage of the sun’s energy which is trapped, and results in an increase in average air temperature.

EPA’s “Causes of Climate Change” website explains the role of greenhouse gas emission in an infographic slide show. The above graphic is from Evidence and Causes, NAS, figure B1

Flooding in Groton following a heavy storm

Flooding from sea level rise, increase in severe storms, and habitat loss from ocean acidification.

While natural causes such as shifts in El Nino and the North Atlantic Oscillation (NAO) can alter temperatures and precipitation patterns, an overwhelming majority of scientists believe that warming temperatures in recent decades are the result of an increase in gases from the burning of fossil fuels, leading to an increase in the “greenhouse effect.” While greenhouse gases are necessary to trap some of the sun’s energy and keep the surface of the planet warm , since the Industrial Revolution began (1800), the concentrations of carbon dioxide, one of the major greenhouse gases, have increased by 40 percent. This buildup of carbon dioxide, combined with increases in other greenhouse gasses such as nitrous oxides (from automobile and power plant exhaust) and methane, causes an increase in the percentage of the sun’s energy which is trapped, and results in an increase in average air temperature.

EPA’s “Causes of Climate Change” website explains the role of greenhouse gas emission in an infographic slide show.

winter flounder in eelgrass habitat

The time period to assess trends with the data available for Long Island Sound conditions is not long enough to say with certainty that environmental trends are the result of climate change or the result of other factors. But several trends are consistent with global trends identified as being caused by climate change.

• Sea level rise. NOAA monitoring stations in the Sound have been documenting local sea level rise for decades, although it is important to note that other factors, such as changes in the relative height of the land as a result of subsidence (gradual caving in or sinking of land) and short-term climatic fluctuations can also play a role. The longest documented tidal height monitoring station in the region has been operating since 1931 in Kings Point, Long Island. Over that time, there has been a mean sea level rise of 2.35 mm/year (0.1 inch per year), the equivalent of almost one inch every 10 years. Other stations in Long Island Sound and the rest of southern New England show similar trends. This rate of rise is similar or slightly higher than global average trends which increased at an average rate of 0.06 inches per year from 1880 to 2012, according to NOAA. Since 1993, however, global average sea level has risen at a rate of 0.11 to 0.12 inches per year—roughly twice as fast as the long-term trend. According to IPCC, Global mean sea-level rise will continue during the 21st century, very likely at a faster rate than observed from 1971 to 2010. The trend is shown in Long Island Sound Study’s climate change indicators’  presentation.
• Change in fish migration patterns. While there are many factors that influence fish populations, resource managers and scientists believe warming temperatures in the Sound and Atlantic Ocean might be favoring the growth and recruitment of southern species over those of more cold-adapted species. Many cold-water species, including lobster and winter flounder, have been declining over the last two decades while many warm water species, including summer flounder and scup are increasing. The trend is shown in Long Island Sound Study’s climate change indicators’ presentation.
• Snow Melt is occurring earlier. Winter snow collects in the hills and mountains of the New England countryside instead of flowing directly into the Connecticut River. As a result, the river, which provides 70 percent of the Sound’s fresh water, usually experiences its lowest flows from January to March. As temperatures rise in the spring, the snow and ice melts. This leads to higher runoff and is referred to as the spring ‘freshet’. By looking at 80 years of river data, scientists at the US Geological Survey and the University of Connecticut have determined that the spring freshet is occurring in Long Island Sound on average about 10 days earlier than it did a hundred years ago. Changes in the timing of the freshet may have implications for some aquatic species and human activities along the coast. Flooded fields and marshes along the river during the freshet provide critical feeding areas for migratory waterfowl. So if the freshet comes earlier, waterfowl could be impacted if they do not adjust the timing of their migration. Changes in the timing of flooding may also provide a competitive advantage to invasive plants (such as purple loosestrife and Phragmites) in the marshes since some of these species emerge earlier than the natives. The trend is shown in Long Island Sound Study’s climate change indicators’ presentation.

NASA Earth Observatory Image of Hurricane Sandy

Scientists cannot determine if any single weather event is the "result" of climate change.

In recent years, Long Island Sound has experienced extreme weather events, including a hurricane, tropical storms, nor’easters, and a freak October blizzard. The storms have led to power outages, flooded streets, uprooted trees, and eroded shorelines.

According to the NAS it is difficult to attribute cause of rare events reliably, particularly if they are also affected by natural climate patterns such as El Nino and La Nina events. But climate models predict an overall increase in storm frequency and severity as Earth’s lower atmosphere is becoming warmer and moister as a result of human-emitted greenhouse gases. This gives the potential for more energy for storms and certain severe weather events. Consistent with these theoretical expectations, heavy rainfall and snowfall events (which increase the risk of flooding) and heatwaves are generally becoming more frequent. Trends in extreme rainfall vary from region to region: the most pronounced changes are evident in North America and parts of Europe, especially in winter. (Evidence and causes, NAS, p. 15). So while we cannot attribute any specific storm event directly to climate change (there were certainly storms on earth long before the industrial revolution), it is likely that the increases in storm frequency and severity we have observed over the last decade are, at least in part, due to changing climate.

Hurricane Sandy whips up Long Island Sound at Kings Point, Long Island, at 4 pm, still four hours prior to making landfall, Monday, Oct 29, 2012. © 2015 Karen Rubin/news-photos-features.com.

Storm surges caused much of the damage during Superstorm Sandy and Hurricane Katrina. They can become more of a threat as a result of higher normal tides that will occur because of sea level rise. Here is a definition:

Storm surge is the abnormal rise of water above the tide levels generated by a storm. It is produced by water being pushed toward the shore by the force of the winds moving cyclonically around the storm. This rise in water level can cause extreme flooding in coastal areas particularly when storm surge coincides with a normal high tide. During Superstorm Sandy, the highest storm surge in the storm was reported in Kings Point, NY on Long Island Sound. It was measured at 14.38 feet above the average low tide.

Yes. There are several things you can do to reduce greenhouse gas emissions.

Governments around the world as well as many states and local municipalities are trying to reduce greenhouse gas emissions in an effort to curb global temperature increases and reduce the risks associated with climate change.  In order for these plans to succeed, citizens will need to do their part. EPA’s Climate Change website has a “What You Can do? Section that highlights   25 simple behavior changes that can be done at home, school, the office, and on the road to that can protect the climate, reduce pollution, and save money. One of these steps is to use EPA’s personal greenhouse gas emissions calculator to estimate your household’s annual carbon emissions. More information is also available in the Municipal Resources section.

In the Town of Bedford, NY, which is partially in the Long Island Sound watershed, Bedford 2020, a community organization, encourages residents to reduce emissions spanning five action areas, including: Energy, Food & Agriculture, Transportation, Waste & Recycling, and Water & Land Use. The goal of this community group is to help the town succeeds in its Climate Action plan goal of reducing greenhouse gas emissions by 20 percent by the year 2020. By January 2015, it has reached 79 percent of that goal.

A reinforced concrete house survives Superstorm Sandy. Photo from Federal Alliance for Safe Homes

Prepare for the potential impacts from climate change.

Even if human emissions of  greenhouse gases completely stopped, it would take a very long time (hundreds of years) for surface air temperature and the ocean to begin to cool because of the excess emissions that are already in the atmosphere. So communities must learn to adapt to climate change. Climate Change Adaptation involves identifying risks associated with climate change and managing them to reduce their impacts. An example of a climate change adaptation strategy is for a community to protect itself from storm surges by building sand dunes. Another example is for a shoreline community to restore underwater habitats such as eelgrass meadows and oyster beds so they can act to help break wave action before it pounds the shore. Preparing for threats is also described as Climate Change Resiliency. Homeowners, for example, can be more resilient to extreme weather events by flood proofing their homes, and, in locations where more severe flooding tends to occur, elevate major home appliances and the electrical system from a level determined to be safe from severe floods.  (Center for Housing Policy fact sheet) The Federal Alliance for Safe Homes (Flash) has a number of resilient strategies on its website www.flash.org. CT Sea Grant has a Hazard Guide for Coastal Property Owners with beaches and dunes  that will help you evaluate threats and identify what you can do to protect your coastal property and the natural environment.

More information about how you can prepare for impacts is available in the Municipal Resources section.