Climate Change Effects and Impacts
The most recent report by the Intergovernmental Panel on Climate Change (IPCC) states that greenhouse gas (GHG) emissions from human activities are responsible for accelerating global warming and climate change. Higher temperatures, more frequent precipitation and storms, faster rates of ocean warming, and sea level rise are some of the key physical effects of climate change that are impacting communities and ecosystems around the world. Climate change impacts will continue to worsen as global temperatures and greenhouse gas emissions increase (see Climate Change webpage).
New York's Responding to Climate Change in New York State (ClimAID) report (2011, 2014) , the National Climate Assessment (2023), DEC Observed and Projected Climate Change in NYS (PDF), and other climate impact assessment reports show that a variety of climate change impacts have already been observed across the northeastern United States and in New York State. These climate change reports clearly show, based on scientific data, that significant climate change impacts are already occurring. People, plants and wildlife, and ecosystems are facing an uncertain future unless adequate actions are taken to adapt to climate change impacts already unfolding and expected to intensify over time. GHG emissions must also rapidly and significantly be reduced in the near future and eventually eliminated to prevent the increasingly harmful impacts of climate change over the next several decades.
The average temperature across the United States (U.S.) has risen at an average rate of 0.16°F per decade since the beginning of the 20th century, increasing to an even faster rate of 0.31 to 0.54°F per decade since the 1970s. Some parts of the U.S., such as the west, Alaska, and Northeast region have experienced greater warming than the rest of the country.
The annual statewide average temperature in New York has warmed 3°F (0.6°F per decade) since 1970. The state's average temperatures are projected to rise by as much as another 3°F by 2080 with the greatest warming occurring in the northern parts of the state. Rising annual temperatures are already having widespread impacts on New York's communities and ecosystems and impacts are expected to increase. New York State's changing climate may no longer be able to support the types of plants, insects, and wildlife living in New York, particularly those in high-elevation regions like the Catskills and Adirondacks. As New York's temperatures increase, these species will extend their range north, impacting the industries and economies that depend on them such as fishing, hunting, and tourism.
Across the northeastern U.S., winters are warming faster than any other season. Over the last century, average winter temperatures have increased by approximately 3°F, spring temperatures by 2°F, and summer and fall temperatures by 1.4°F.
In New York, winters have warmed three times faster than summers. Warmer winter temperatures, with fewer days below freezing, are bringing more winter precipitation to New York as rain, less snow, reduced snow cover, and earlier spring snowmelt. Less snowfall and earlier snowmelt are already having and will continue to have increasing economic impacts on New York's winter recreation industry. Reduced snow cover will increase the vulnerability of certain plants that depend on snow for insulation, and wildlife that depend on snow for protection from predators during the winter. Less snowfall in the winter can also cause drier summer soil conditions, increasing the risk of wildfires. Lake effect snow will increase snowfall amounts in the next few decades for parts of New York State, as warmer winters continue to cause less ice cover on Lake Erie, Lake Ontario, and the Finger Lakes. However, lake-effect snow will eventually decrease with continued global warming, as temperatures below freezing in New York become less frequent and more winter precipitation falls as rain.
Warmer winters in New York are also affecting the winter-spring season transition, impacting the timing of blooming for trees and flowers which migrating and hibernating wildlife depend on for food. Changes to the timing of the winter-spring transition can also impact agriculture by extending the length of the growing season, with the last frost of winter occurring earlier in the year. Although increasing the length of the growing season can have advantages, it can also impact the types of crops that can be grown, encourage invasive species, weed growth, and crop diseases, and increase demand for irrigation. Deciding on the right timing for late winter tapping of maple trees for producing maple syrup, a commercially important commodity for New York, is expected to become more difficult.
Shifting seasons can also impact natural ecosystems, plant productivity, and forest health. Warmer late-winter and early-spring temperatures can expand the geographic range and population size of invasive insect species that harm native vegetation, such as the emerald ash borer and southern pine beetle. Warmer winters also can extend the season for disease-carrying species like ticks and mosquitoes.
In addition to warmer average temperatures, recent decades have shown changes in the frequency and intensity of extreme temperature events, such as heat waves and cold waves. The frequency of cold waves has decreased across most of the United States over the last century, while the number and length of heat waves have been increasing each decade since the 1960s. The annual frequency and length of heat waves in New York State are expected to continue to increase.
Extreme heat will have a greater impact on urban areas which have many heat-absorbing surfaces like roads, parking lots, and buildings, and few cooling green spaces and trees. This "heat island effect," when urban areas experience higher temperatures than the surrounding suburban or rural areas, increases the risk of heat-related illnesses and death for urban residents, particularly for vulnerable populations like the elderly. Extreme heat can also stress infrastructure, like electrical transmission lines, railroad tracks, and airport runways.
Extreme temperature events like heat waves can impact agriculture production and revenue by stressing crops and livestock, worsening drought conditions, and increasing the need for irrigation. As the frequency and duration of heat waves increase, the impacts on agriculture could be felt by all New Yorkers through rising food costs. In addition to increasing risks to human, animal, and ecosystem health, prolonged periods of extreme heat increase energy demand for cooling using air conditioners, producing more greenhouse gas emissions and worsening future warming and climate change.
Ocean and coastal temperatures along the northeastern U.S. have increased by 0.06°F per year from 1982 to 2016 and are projected to continue to warm faster than most marine waters around the world. Warming oceans contribute largely to sea level rise but are also affecting the productivity and distribution of many marine species and ecosystems. Warming oceans are already impacting the economies of New York's commercial fishing and tourism industries, as well as the economies of local communities that depend on the revenue from those industries.
Increasing ocean temperatures are causing fish to move north to deeper, colder waters, changing the populations of marine species found in the waters off New York's coasts. Rising ocean temperatures have also affected the productivity of marine populations. Species like northern shrimp, surf clams, and Atlantic cod, are declining as waters warm, while other species, such as black sea bass, are experiencing increased productivity. Some species, such as American lobster and surf clam, have declined in regions where temperatures are higher but have increased in cooler northern areas that benefit from species migrations. Changes to the distribution of fish species due to warming oceans are requiring some fishermen to travel farther to catch certain species or target new species that are becoming more abundant as waters warm. However, challenges exist between keeping up with the industry response to changing fishery populations and the State's fisheries management and conservation strategies.
Climate change can influence the intensity, frequency, and even type of precipitation that a region experiences. Average temperatures of oceans are rising as more heat is absorbed from the warming atmosphere, increasing the amount of water that evaporates into the air. As the moisture-saturated air moves over land, it can produce more intense precipitation and high humidity. Total annual precipitation has increased over land areas both globally (0.10 inches per decade) and in the U.S. (0.20 inches per decade) over the last century.
The northeastern U.S. experienced an over 70% increase in heavy precipitation from 1958 to 2010, greater than any other region in the country. Heavy precipitation refers to instances when the amount of precipitation received substantially exceeds what is normal for that location. Precipitation is expected to increase in New York, with longer and more frequent precipitation events, and heavier downpours.
Increased precipitation through more frequent and intense rain events is impacting New York by increasing flooding throughout many parts of the state. Flooding from heavy precipitation can result in costly damage to homes, roads, bridges, and other important infrastructure. Wetter growing seasons can affect agricultural production by damaging crops and flooding farmlands, impacting food-chain supplies and costs. Rainfall can also contribute to water pollution by washing sediment and chemicals from impervious surfaces such as roads, building roofs, and parking lots into nearby water bodies, known as stormwater pollution. In severe situations, a heavy rainfall can create an excessive amount of stormwater that can overwhelm stormwater systems and sewage treatment systems that can overflow into rivers, streams, and other surface waters. Nutrient runoff from fertilized lawns, septic systems, and other sources following more frequent heavy rainfall events has led to an increase in harmful algal blooms (HABs) in many New York water bodies. Combined with warmer water temperatures, HABs are occurring more often and lasting longer throughout the year. Algal blooms are harmful to humans, animals, fish, and shellfish populations, as well as sensitive ecosystems like eelgrass beds.
Snowfall in New York is likely to decrease. Due to warming global temperatures, many regions are seeing a decrease in winter precipitation falling as snow and an increase in winter rain. The combination of less early winter snowfall and earlier snowmelt will lead to a shorter snow season. This results in fewer days with snow on the ground, decreased snow depth, and earlier snowmelt, impacting ecosystems and industries in New York that depend on snow.
Sea Level Rise
Sea level rise (SLR) is the most direct and observable effect of climate change in New York. Warming oceans are causing global SLR through a process called thermal expansion- an increase in the volume of ocean water as it warms- and through the melting of land-based ice (glaciers). Between 1971 and 2018, thermal expansion, glacial ice loss, and loss of ice sheets were major contributors to SLR. Other factors, such as changes to land-water storage (i.e., holding water in dams and reservoirs, river runoff from groundwater extraction, inland sea, and wetland drainage) were responsible as well, but to a lesser extent. Changes in sea levels are not the same around the planet. Differences in ocean circulation and temperature, wind patterns, salinity, and density are just a few factors that influence sea surface height and the amount of SLR for a particular location. Data collected shows that sea levels along the mid-Atlantic coast are rising three to four times faster than the global average.
Geological records of Earth's history show that sea levels have risen and fallen during Earth's periods of warming and cooling. During past warming periods millions of years ago when global temperatures were around 1.5-3.6°C above preindustrial levels, global average sea levels could have been as much as 100 feet higher than they are today. Global average sea levels have risen 8-9 inches since 1880, a third of that rise occurring in the last 25 years. The IPCC is "virtually certain" that SLR will continue through the 21st century and for centuries to come due to continued ocean warming and ice sheet melt. Global average sea levels are predicted to rise 2-3 meters in the 21st century, even if drastic GHG reductions are successful in limiting global warming to 2°C.
The Atlantic coast is particularly vulnerable to SLR because much of its land is flat and close to sea level, posing a serious risk to the region's coastal ecosystems and the millions of people that live in urban areas in coastal floodplains. Because coastal communities are home to more than half of New York's residents, SLR has become an issue that cannot be ignored. Coastal flooding is a problem being worsened by SLR. Higher water levels from SLR are causing high-tide flooding in coastal and inland New York communities not previously impacted by tidal flooding, and intensifying storm surges that threaten homes and infrastructure. Natural ecosystems like wetlands help to buffer inland areas from storm surges, acting as a sponge for coastal flooding. As sea levels rise, these wetland ecosystems need to adapt by moving inland or raising vertically or they will be submerged and destroyed. However, the rapid rate of SLR and accelerating coastal development are limiting how much these ecosystems can adapt. Losing the protection of natural coastal wetlands to SLR increases the vulnerability of New York communities to climate change.
Sea levels along New York's coast and in the Hudson River have already risen more than a foot since the year 1900 (about 1.2 inches per decade). The tidal coasts of Long Island, New York City, and the lower to mid-Hudson River are three regions of the state currently experiencing, and vulnerable to future SLR. The New York State Community Risk and Resiliency Act (CRRA) directed DEC to adopt science-based SLR projections to ensure that decisions regarding certain state permits, regulations, and expenditures include consideration of the effects of climate risk, like sea-level rise.
Identifying trends and measuring the influence of a warming climate on storm activity and behavior can be a challenge because of the great degree of variability in the conditions and mechanisms by which a storm forms. There are also limits to using available historical data when they are no longer adequate for generating precise predictive models as climate change is transforming the dynamics of systems. What is known is that cyclones (hurricanes, tropical storms, and other intense rotating storms) and extratropical cyclones (nor'easters) get their energy from warm, moist air enhanced by warming ocean waters. When cyclones make landfall, they bring intense rainfall and high winds that can push large volumes of ocean water, known as storm surge toward shore. Storm surge is one of the most dangerous impacts of cyclones. Storm surge can cause severe flooding and damage along coastlines, as well as up rivers and streams. Storm surge is worsened by rising sea levels. Changes in cyclone frequency and intensity, including the rapid rate at which storms can intensify, are being influenced by climate change and especially rising ocean surface temperatures.
Extreme storm events are becoming a greater threat to New York State. Approximately 65 tropical or subtropical cyclones have struck New York as hurricanes or tropical storms since the mid-19th century. In 2011, Hurricane Irene and Tropical Storm Lee hit the east coast back-to-back, bringing damaging winds, extreme precipitation, and significant flooding to eight upstate New York counties. In 2012 Superstorm Sandy hit the east coast of the United States with heavy rains, strong winds, and record storm surge, causing catastrophic damage to the New Jersey shore, New York City, Long Island, and other coastal regions of the northeast. Hurricane Sandy caused over $60 billion in damages, caused widespread power outages, disrupted transportation and the region's supply chain, and physically altered New York's coastline.
Other Impacts of Climate Change Around New York State
Climate change is impacting New York State in many ways. Warmer temperatures are altering the diversity of plant and wildlife species in the state's forests, lakes, and streams, as well as expanding the range of invasive species that are destroying native ecosystems. Longer and more frequent heat waves are stressing New York's agricultural sector, energy systems, transportation infrastructure, as well as the health and safety of residents. Increased precipitation is causing more severe inland flooding along the Great Lakes and in river valleys. Sea level rise is worsening flooding, erosion, and storm surge along the coasts of Long Island and New York City, and in tidal sections of the Hudson River. New York will continue to experience greater environmental, economic, and social impacts from climate change unless efforts are ramped up to mitigate and adapt to worsening impacts.
Climate Change as a Threat Multiplier
Scientists have recognized climate change works as a global threat multiplier. The direct effects of climate change, like extreme heat, sea level rise, and intensifying storms are exacerbating other social threats or stresses, such as poverty, famine, and immigration. For example, climate change is a significant threat to the global food supply. Changes to regional temperature and precipitation affect crop production and threaten food security around the world. Warming decreases yields of several staple crops in major growing regions, with an approximately 5-15% yield loss per degree Celsius of warming. Declines in crop production not only threaten accessibility to food and cause famine, but the resulting increase in food costs and loss of agricultural jobs and revenue in regions that depend on them can also exacerbate poverty.
The United States Department of Defense 2021 Climate Risk Analysis Report states "Increasing temperatures; changing precipitation patterns; and more frequent, intense, and unpredictable extreme weather conditions caused by climate change are exacerbating existing risks and creating new challenges. Without adaptation and resilience measures, climate hazards, particularly when combined with other stressors, are likely to contribute to political, economic, and social instability around the world."
Regions that do not have the resources to respond to or recover from climate change and its impacts experience migration of residents in search of better conditions. Emigration out of these areas and immigration into the United States can be driven, for example by the flooding and loss of coastal homes and entire communities due to sea level rise. Climate migration can also occur because climate change exacerbates famine, lack of access to healthcare, employment and housing, and even underlying political, social, and economic stressors. Immigration as a result of the rapid influx of large numbers of climate migrants can create similar conditions and stressors in the new location-the receiving community-by placing added stressors on food supply, housing, and essential resources if the new community is not prepared and has not built adaptive capacity.
The Disproportionate Impact of Climate Change and Climate Justice
Environmental justice is the fair and meaningful treatment of all people, regardless of race, income, national origin, or color, with respect to the development, implementation, and enforcement of environmental laws, regulations, and policies. Evidence shows that climate change disproportionately impacts certain communities, ethnic groups, and economic classes because of underlying historical disparities and inequities. These groups are often already located in higher-risk areas like flood zones and do not have the access to many resources and services that would help them prepare for, recover from, and adapt to the impacts of climate change. Awareness of the critical need to address climate justice issues is increasing as climate change impacts continue to increase in disproportionate severity.
The Climate Leadership and Community Protection Act (Climate Act) directed the DEC, in cooperation with the New York State Energy Research and Development Authority (NYSERDA), and New York Power Authority, and with input from relevant agencies, the Climate Action Council, and the Climate Justice Working Group, to develop New York State's Disadvantaged Communities Barriers and Opportunities Report (PDF) to assess why some New York communities are disproportionately impacted by climate change and air pollution and have unequal access to clean energy. The report identifies the barriers that affect these communities' access and participation in certain services and commodities such as:
- Distributed renewable energy generation.
- Energy efficiency and weatherization investments.
- Zero-emission and low-emission transportation options.
- Adaptation measures to improve the resilience of homes and local infrastructure to the impacts of climate change.
- Other services and infrastructure that can reduce the risks associated with climate-related hazards, including but not limited to:
- Shelters during flooding events.
- Medical treatment for asthma and other conditions that could be exacerbated by climate-related events.
The report provides recommendations, and opportunities to serve as an initial step in the process of ensuring that disadvantaged communities across the state have access to, and community ownership of, the services and commodities needed to mitigate and adapt to climate change. The report's recommended actions will be included, as appropriate, into the New York State's Climate Action Council's final scoping plan, paving the way for the benefits of clean energy and a safe and healthy environment for all New Yorkers.
DEC's Office of Environmental Justice (OEJ) is the lead for State agency efforts to address environmental equity issues and concerns, including climate justice concerns, that affect primarily low-income and minority communities. OEJ provides disproportionately impacted residents and communities with access to resources and tools across all DEC's operations to address environmental justice and climate justice concerns.
Projections for Future Climate Change Impacts
The scientific evidence shows that climate change impacts will become more severe over time with the continuing rise of global warming from GHG emissions. How severe future climate change impacts will become depends on how much GHG emissions can be rapidly reduced and how quickly an adequate level of effective climate change resilience and adaptation measures can be implemented. Below are official sea level rise projections and several resources on projections of future climate change impacts for New York State
Sea Level Rise Projections for New York State
The table provides projections for New York State based on projected rates of low, low-medium, medium, high-medium, and high sea level rise for the Long Island, New York City/Lower Hudson, and Mid-Hudson regions. Throughout the state, development, land use, and infrastructure decisions made now will determine how vulnerable future generations will be to rising sea levels.
New York City/Lower Hudson
The IPCC reports that global warming is likely to reach 1.5°C above pre-industrial levels between 2030 and 2052 if temperatures continue warming at the current rate, resulting in:
- Increases in average temperatures, hot extremes, heavy precipitation, and probability of drought
- Continued sea level rise past the year 2100
- Loss of geographic range for many insect, plant, and vertebrate species
- Northward shifts in the range of many marine species
- Increases in climate-related risks to health, livelihoods, food security, water supply, human security, and economic growth
The 5th National Climate Assessment (NCA)is a congressionally mandated comprehensive report that assesses changes in the climate, its national and regional impacts, and options for reducing present and future risk. Key messages in the 5th NCA include:
- Every region of the country is already experiencing the impacts of climate change
- Without rapid and deep reductions in global GHG emissions from human activities, the risks of accelerating sea level rise, intensifying extreme weather, and other harmful climate impacts will continue to grow
- Adapting to climate change impacts that are already occurring is necessary, especially in underserved and overburdened communities that face disproportionate risks because of social and economic inequities.
NOAA National Centers for Environmental Information State Climate Summaries provide future climate projects for New York State for high and low emission scenarios. Projected changes for New York State include:
- Historically unprecedented warming during this century, even under a low-emission scenario
- Increase in sea level rise more than global projections
- Increase in tidal flood days
- Increased winter precipitation falling as rain rather than snow
IPCC's second installment of the Sixth Assessment Report provides a comprehensive look at intensifying climate change impacts and future risks, particularly for resource-poor countries and vulnerable populations. Key messages in the report include:
- Extreme events like heatwaves, heavy rainfall, and droughts will increase in frequency and intensity with continued global warming
- The impacts of climate change will be worse if warming exceeds 1.5°C
- Adaptation to climate change impacts is necessary now and for the future, even if GHG emissions are reduced
NYSERDA assembled a team of New York-based and national climate science experts to collaborate on an assessment report that will update the state's 2014 climate change projections from the "Responding to Climate Change in New York State" report. The updated climate change impacts assessment will help residents, businesses, and policy-makers across New York State plan and prepare for climate change impacts and articulate the benefits of taking action to adapt to future climate conditions. The assessment will include:
- Up-to-date projections of future climate conditions in New York State
- In-depth economic impact assessments
- Adaptation strategies and case studies
The New York State Climate Impacts Assessment is anticipated to be released in early 2023.
Mitigating and Adapting to Climate Change
Minimizing the vulnerability to the current and future impacts of climate change requires immediate action. Mitigating future climate change by rapidly and significantly reducing and eventually eliminating GHG emissions is critical for avoiding the worst-case projections for the future. To address currently unfolding climate change impacts, reducing GHGs will not be enough. Planning and implementing adaptation and resilience measures are essential for reducing risks and vulnerabilities, building adaptive capacity, and even identifying ways to take advantage of any benefits of climate change. Improving our capacity to understand, anticipate and prepare for climate change impacts now can reduce community vulnerability and risk to worsening climate impacts in the future. New York State agencies and local governments are taking progressive action to both mitigate and adapt to climate change and becoming more resilient to climate change impacts.