NRWA Climate Change Glossary
The following terms are defined as they are used on the Nashua River Watershed Association's website.
Adaptation
Adjustments that societies or ecosystems make to limit the negative effects of climate change or to take advantage of opportunities provided by a changing climate (EPA definition).
Aquatic Buffers
Undeveloped area along a shoreline, wetland, or stream that protects the water body, filters runoff, and provides a corridor for movement and migration by wildlife.
Biodiversity
The variety of living species on Earth, including plants, animals, bacteria, and fungi. Scientists have estimated that there are around 8.7 million species of plants and animals in existence (National Geographic definition).
Biomes
Communities of flora and fauna that tend to exist together, such as the northern hardwood-hemlock-pine forests and central deciduous-oak-hickory forests found in the Nashua River watershed.
Carbon Cycle
The process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere (NOAA definition).
Carbon Footprint
The total amount of greenhouse gases that are emitted into the atmosphere each year by a person, family, building, organization, or company.
Carbon Sequestration
Processes by which trees and plants absorb carbon dioxide, release oxygen, and store carbon.
Climate Change
A significant change in the measures of climate lasting for an extended period of time. Climate change includes major changes in temperature, precipitation, or wind patterns, among others, that occur over several decades or longer.
Climate Impact
A negative effect on a natural system due to climate change.
Conservation
The protection, preservation, management, or restoration of natural environments and the ecological communities that inhabit them (USDA definition).
Corridor
Connectivity through relatively narrow, linear strips of land or water. Upland strips normally contain cover.
Deforestation
Human-driven and natural loss of trees, which affects wildlife, ecosystems, weather patterns, and climate.
Ecology
The study of the relationships between living organisms, including humans, and their physical environment.
"Flash" Drought
Short but severe drought conditions due to extraordinary heat and dryness, often caused by climate change.
Fluvial Geomorphology
The study of the interactions between the physical shapes of rivers, their water and sediment transport processes, and the landforms they create.
Fossil Fuels
Decayed organic matter from plants that accumulated in the earth over eons and is extracted primarily in the form of coal, oil or natural gas for use as energy for transportation, heating, and industrial purposes.
Greenhouse Effect
Retention of the sun's warmth in the Earth's lower atmosphere by greenhouse gases, primarily water vapor, carbon dioxide, methane, nitrous oxide and fluorinated compounds.
Greenway
A corridor of undeveloped land preserved for recreational use or environmental protection, often along a river. Naturally vegetated greenways may protect river corridors and serve as aquatic buffers.
Groundwater
Water that exists underground in saturated zones beneath the land surface. The upper surface of the saturated zone is called the water table (USGS definition).
Habitat
Place where an organism makes its home. A habitat meets all the environmental conditions an organism needs to survive, including shelter, water, food, and space (National Geographic definition).
Habitat Fragmentation
Division of large, contiguous, landscapes into smaller, unconnected areas. Fragmentation can be caused by construction of roads, homes, subdivisions, commercial and industrial activities, and other human development and can negatively impact wildlife.
Hydrology
The branch of science concerned with the properties of the earth's water, and especially its movement in relation to land.
Infiltration
The process by which water on the ground surface enters the soil. If the rate of precipitation exceeds the rate of infiltration, runoff will usually occur unless there is some physical barrier.
Invasive Species
Plants, animals, and other living organisms that are non-native (or alien) to the ecosystem and can negatively alter the environment, such as by displacing native plants or creating monocultures.
Landscape Connectivity
The degree to which a landscape facilitates or impedes movement for animals and plants.
Landscape Permeability
Developed landscapes that retain adequate natural areas to provide habitat or allow migration of wildlife and plants.
Low Impact Development
Systems and practices that use or mimic natural processes that result in the infiltration, evapotranspiration, or use of stormwater in order to protect water quality and associated aquatic habitat (EPA definition).
Meadow
An open habitat, or field, vegetated by grass, herbs and other non-woody plants. Meadows provide habitat for birds and wildlife, help to infiltrate water, protect against drought, and sequester carbon.
Mitigation
Human intervention to reduce the impact on the climate system including strategies to reduce greenhouse gas sources and emissions and enhance greenhouse gas sinks.
Municipal Vulnerability Preparedness Program (MVP)
Technical assistance available in Massachusetts for towns and cities to complete climate change vulnerability assessments, develop action-oriented resiliency plans, and implement top-priority climate change resilience projects.
Nature-Based Climate Solutions
Protecting or managing natural systems to mitigate climate impacts. Some Nature-Based Climate Solutions directly combat climate change by sequestering and storing carbon.
Non-Point Source Pollution
Non-point source pollution includes contaminants from surface runoff, groundwater discharge, sediment leaching, and atmospheric deposition. Pollution from many diffuse sources, such as fertilizers, oil and grease, road salt, and animal waste. These can be carried by rainfall or snowmelt runoff into waterways where they have harmful effects on drinking water supplies, recreation, fisheries and wildlife (EPA definition).
Paleoclimatology
The study of ancient climates, prior to the widespread availability of instrumental records, using records of climate conditions preserved in tree rings, locked in the skeletons of tropical coral reefs, sealed in glaciers and ice caps, and buried in laminated sediments from lakes and the ocean (NOAA definition).
Permeable Surface
Surfaces that let water pass through into the soil below. Unlike asphalt and concrete, permeable materials allow natural infiltration and slow the runoff of rainwater.
Pollinators
Anything that helps carry pollen from the male to female parts of flowers. Plants that are not self-pollinating depend on wind, water, birds, bees, butterflies, beetles, bats, and other small mammals for fertilization and the production of fruits, seeds, and young plants.
Pollinator Plants
Flowering plants that provide nectar or pollen for a wide range of pollinating insects. Planting a pollinator garden supports the health of pollinators such as honey bees, native bees, and monarch butterflies.
Rain Garden
A vegetated landscape depression that collects rainwater from a roof, driveway, parking area, or street and allows it to soak into the ground. Benefits of planting rain gardens include slowing the flow of runoff, filtering out pollutants, and providing food and shelter for wildlife.
Renewable Energy
Energy resources that are often considered naturally replenishing such as hydro, geothermal, solar, wind, ocean thermal, wave action, and tidal action.
Reserve
A large resilient or resistant, protected area where climate-induced changes occur in a manner that allows plant and animal communities to migrate or adapt.
Resilience
A capability to anticipate, prepare for, respond to, and recover from significant multi-hazard threats with minimum damage to social well-being, the economy, and the environment (EPA Definition).
Resistance
The ability of an ecosystem or population to persist and remain relatively stable in response to climate change or other stress. Landscapes that are resistant are particularly important for species that require specific habitat or have little ability to migrate, such as vernal pool species.
Restoration
Actions to reverse the current climate change trends and to restore the Earth to a healthy climate for humanity's well-being.
Sedimentation
In rivers, eroded or discharged organic and inorganic material transported by water that settles out as the water flow slows.
Stormwater
Runoff generated from rain and snowmelt events that flows over land or impervious surfaces, such as paved streets, parking lots, and building rooftops, and does not soak into the ground (EPA definition). It often carries contaminants, such as sediment, heavy metals, organic molecules including oil & grease and pesticides, nutrients such as nitrogen and phosphorus, and pathogens.
Stormwater Infrastructure
Traditional "gray" infrastructure refers to curbs, gutters, drains, piping, and collection systems that collect and convey stormwater into a series of piping that ultimately discharges untreated stormwater into a local water body. "Green" stormwater infrastructure is designed to mimic nature and capture rainwater where it falls, reducing the volume of pollutants, such as sediment, nitrogen and phosphorus, entering our waterways (EPA definitions).
Sustainable Development
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs (UN definition).
Sustainability
A state in which the demands placed on the environment can be met without reducing its capacity to allow all people to live well, now and in the future.
Vernal Pool
An isolated wetland that is a shallow pool that fills in the spring and dries up annually or every few years. They supply essential breeding habitat for several species of animals, particularly amphibians, because they lack a fish population that would otherwise prey on them.
Watershed
An area of land that drains all the streams and rainfall to a common outlet such as the outflow of a reservoir, mouth of a bay, or any point along a stream channel (USGS definition).
Wetlands
Areas where water covers the soil, or is present either at or near the surface of the soil, all year or for varying periods of time during the year, including during the growing season (EPA definition).
Climate Change and the Nashua River Watershed
The changing climate of New England is profoundly affecting the Nashua River watershed. Although climate news often centers on increased storms and sea level rise around the globe, impacts to our local rivers, wetlands, and ecosystem - the core of the extraordinary landscape in our watershed - require our attention now. These are areas in which the NRWA has unique expertise and experience.
The information and links on this website focus on local impacts, actions that local communities can take to reduce impacts and prepare for the future, and the NRWA's role as a regional environmental leader. Over the last 50 years, the NRWA has directly and indirectly helped to mitigate the impacts of a changing climate through a wide range of programs.
Climate Change in Our Region
The primary climatic impacts experienced in New England are the increase in the total amount of rainfall and rising temperatures. Notably, the National Weather Service reports that the frequency and intensity of strong rainfall events are increasing more in New England than anywhere else in the United States. Since most rainfall increases are occurring in the winter and early spring when the ground cannot absorb water, water is lost to runoff rather than recharging groundwater. As temperatures increase, we are experiencing a significant increase in the number of days over 90 degrees. In addition, the freeze-free period in New England is lengthening, and conversely the number of days of extreme cold is diminishing. These changes in rainfall events and intensity, and warming temperatures, are having a major impact on our ecology.
Warming Seas in the Gulf of Maine: In the past three decades, the Gulf of Maine, just to our east, has warmed three times faster than the global average. Over the past 15 years, the basin has warmed at seven times the global average. The Gulf has warmed faster than 99 percent of the global ocean. (August 8, 2018. NASA Earth Observatory images by Lauren Dauphin, and sea surface temperature data from Coral Reef Watch. https://climate.nasa.gov/news/2798/watery-heatwave-cooks-the-gulf-of-maine/)
Global Warming is Having Local Impacts
Here in Massachusetts and New Hampshire, an increase in the frequency and intensity of rainfall events will stress our existing infrastructure, which was not designed to withstand such challenges. Areas that have been developed or otherwise disturbed are vulnerable to flooding and damage. In addition, if the rate of warming is not slowed, our local climate is expected to resemble the current climate of New Jersey within the next 20 to 40 years, and the current climate of South Carolina within the next 50 to 70 years. In the process of undergoing these changes in such a short period, many of our native plants and animals, including birds and pollinators, are expected to become stressed and may no longer be able to survive in our climate. This will have major impacts on our region’s agriculture, forests, wetlands, and landscape, and thus our overall quality of life.
Migrating State Climate: Changes in average summer heat index—a measure of how hot it actually feels, given temperature and humidity—could strongly affect quality of life in the future for residents of the Northeast. Red arrows track what summers could feel like in Massachusetts over the course of the century under the higher-emissions scenario. Yellow arrows track what summers in Massachusetts could feel like under the lower-emissions scenario. (Frumhoff et al. 2007, Northeast Climate Impact Assessment/Union of Concerned Scientists)
Climate Change and the NRWA
The NRWA is committed to working with communities, organizations, and individuals throughout our watershed to build a more resilient and sustainable landscape that is better able to adapt to a changing climate. The NRWA Board adopted the following policy to reflect this commitment:
NRWA Climate Change Policy: "The Nashua River Watershed Association recognizes the adverse impacts of climate change to the natural systems that sustain life on our planet. It is the policy of the NRWA to promote and undertake local and regional actions to address the impacts of climate change on our watershed. These actions include developing strategies to address changes in local hydrology and ecology, assisting communities to become more resilient, and helping people to live more sustainably and safely in the face of climate change."
The NRWA’s on-going effort to create a greenway corridor along our rivers through land preservation helps to mitigate the effects of flooding by keeping these lands, and associated wetlands, undeveloped and, therefore, better able to absorb excessive rainfall and prevent flooding. Working with federal, state, local, and private entities, the NRWA has encouraged conservation of forests, which helps with carbon sequestration. Our water quality monitoring program has collected information on temperature and other data in our rivers and streams for several decades and serves as an important basis for noting trends caused by a changing climate. The data are shared with the public, the Massachusetts Department of Environmental Protection, and the NH Department of Environmental Services; data are also utilized by the U.S. Environmental Protection Agency.
The NRWA works with municipalities on improving stormwater infrastructure, low impact development, and other best management practices that help them plan for development while protecting critical resources. Our environmental education programs in schools and for the general public have educated tens of thousands of children and adults on the value of wetlands and the importance of managing storm water and the hydrologic cycle at a watershed scale.
All in all, over the last fifty years, the NRWA’s work to fulfill its mission has helped to mitigate the impacts of a changing climate, and our current work is continuing to do so.
What is a watershed? A watershed is a geographic area of land in which all surface and ground water flows downhill to a common point, such as a river, stream, pond, lake, wetland, or estuary. "Healthy, resilient watersheds are the best insurance policy for a changing climate." (USDA, Forest Service, https://www.fs.fed.us/kidsclimatechange/products/water-climate-brochure.pdf)
Climate Change Causes
The Science Behind Our Changing Climate
To gain an understanding of what is causing our climate to change, let us take a brief look at measurements that scientists such as those at NASA and the U.S. National Oceanographic and Atmospheric Administration (NOAA) have been tracking for many years.
Scientists are in agreement that the global climate is rapidly warming and that the causes are rooted in human activity, predominantly combustion of fossil fuels and land use changes such as deforestation. Some of the clearest evidence that global climate change is occurring and is being caused by human activity comes from carbon dioxide (CO2) levels in the atmosphere. The following graph shows atmospheric CO2 levels over the past 800,000 years:
Historical levels of carbon dioxide. This graph, based on the comparison of atmospheric samples contained in ice cores and more recent direct measurements, provides evidence that atmospheric CO2 has increased since the Industrial Revolution. (https://climate.nasa.gov/evidence/)
It is evident that while atmospheric CO2 levels do naturally fluctuate, today’s levels are the highest in millennia. Carbon dioxide levels are much higher than they would otherwise be if humans were not burning so much fossil fuels (oil, gas, and coal), which give off CO2 when they burn.
By studying hundreds of thousands of years of geological data, scientists have shown that temperatures increase when CO2 levels increase, so the current spike in carbon dioxide is certain to result in a rapid additional increase in global temperature.
Historical temperature levels. Temperature histories from paleoclimate data (green line) compared to the history based on modern instruments (blue line) suggest that global temperature is warmer now than it has been in the past 1,000 years, and possibly longer. (Graph adapted from https://earthobservatory.nasa.gov/features/GlobalWarming/page3.php)
The paleoclimate record reveals that the current climatic warming is occurring much more rapidly than past warming events.
What is the Greenhouse Effect?
The greenhouse effect refers to the retention of the sun's warmth in the Earth's lower atmosphere by greenhouse gases. These gases (primarily carbon dioxide, methane, and nitrous oxide) act as a thermal blanket for the planet, warming the surface to what has been a life-supporting global average of 59 degrees Fahrenheit (15 degrees Celsius). The recent rapid increase in greenhouse gases has resulted in the atmosphere trapping more solar radiation and, in turn, raising the global temperature. There are three main sources of greenhouse gases:
- Carbon in Fossil Fuels: A major source of carbon in our atmosphere has been from the accumulation in the earth, over eons, of decayed organic matter from plants. Its longest-lasting deposits are coal, oil, and natural gas. Under natural conditions, these types of carbon slowly accumulated and remained stored in the Earth. However, over the past two centuries or so, humans have been extracting them and utilizing these “fossil fuels” for energy, by burning them for transportation, heating, and industrial purposes. Thus, carbon that took millions of years to be taken up from the atmosphere and accumulate underground gets released back into the atmosphere in a short period of time. The rate of extraction and burning has increased over recent decades, adding to atmospheric CO2 levels.
- Plants and the Carbon Cycle: Changes in land use, such as deforestation, have reduced the overall number of green plants on earth available to take up carbon dioxide from the atmosphere. Green plants absorb CO2 through their leaves and convert it to energy-rich organic compounds in the process of photosynthesis. Trees, for example, use those compounds to form their woody stems and roots. Thus, as plants grow, carbon gets stored in them. When they die, that carbon gets decomposed by microorganisms and fungi, with the result that a significant fraction gets stored in the soil in the form of organic matter. A portion of that carbon gets released back into the atmosphere as CO2, where it can then be taken up again by plants. This circular process is known as the carbon cycle. But the loss of forests worldwide (deforestation) to other uses such as mining, agriculture, urban and suburban sprawl, has led to fewer forested acres to sequester and store the ever-increasing amount of CO2 in the atmosphere, with less stored in plant tissue or in the soil.
- Methane Gas: Methane is a very powerful greenhouse gas that is released to the atmosphere as a result of the natural fermentation of organic matter (for example from swamps). However, increasingly it is being emitted by ruminants (e.g., cattle, sheep, goats, and their relatives) as the world's population expands its need for food, from landfills, and from the extraction and leakage of natural gas from wells and pipelines. It has also been predicted and hypothesized that as temperatures rise, methane trapped by permafrost in northern boreal forests and methane trapped beneath the oceans will begin to be released into the atmosphere.
The vast majority of scientists agree that combustion of fossil fuels is the single largest driver of rising temperatures and climate change. If the release of CO2 is not slowed, the costs to society of addressing its impacts will become staggering. The increasing availability of renewable forms of energy, such as solar, wind, and hydroelectric power, offers options for meeting energy needs. Fortunately, the cost of renewable energy can be competitive with gas and oil.
Banner graphic: https://www.nasa.gov/press-release/nasa-releases-detailed-global-climate-change-projections.
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