Why the Climate is Changing
Climate Science and the Impacts of a Changing Climate
New York bases its climate policies on scientific studies spanning more than two decades and including the entire globe, and also on regional downscalings of this data that project the local consequences of ever-rising greenhouse gas concentrations and the resultant changes in our climate. Websites of the US Environmental Protection Agency and other government agencies (see links on right) provide continually updated information about climate science.
What Causes Climate Change
Earth's climate is subject to natural variation. However, the changes we currently see in our climate result largely from human activities, which have rapidly boosted atmospheric concentrations of carbon dioxide (CO2) and other heat-trapping greenhouse gases. In the past 150 years, atmospheric concentrations of these gases have risen to their highest levels in 650,000 years. The measured global average temperature also has risen, especially during the past three decades, and the planet's vast climate system is changing in response.
Many human activities contribute greenhouse gases to the atmosphere, but the biggest contributor is combustion of fossil fuels (coal, oil and natural gas), which releases large amounts of long-lasting CO2 to the air. Other greenhouse gases, especially methane, nitrous oxide and halocarbons, also are generated by fuel combustion and by agricultural and industrial processes.
Greenhouse Gas Emissions in New York
(Note: Because CO2 is by far the most common human-produced greenhouse gas, the climate-changing potency of any greenhouse gas is expressed as a multiple of the heat-trapping ability of carbon dioxide, called "carbon dioxide equivalent" or "CO2e".)
In 2007, the last year for which complete measurements are available,
- Total greenhouse gases released by human activities in New York State had a CO2e of 284 million tons. This represents an average of 14.7 tons of CO2e for every New Yorker.
- Combustion of fossil fuels generated nearly nine-tenths of the greenhouse gases (predominantly CO2) emitted in New York. One-fourth of New York's CO2 came from the generation of electric power, with the remainder originating about equally from the transportation sector and from industrial, residential and commercial on-site fuel combustion.
- Processes other than fossil fuel combustion produced greenhouse gases with CO2e of approximately 37 million tons.
Compared with other states, New York emits relatively low amounts of greenhouse gases per capita. This is because New York gets less electric power from coal-fired plants (which are the biggest emitters), and because public transportation is widely used in its large cities. Nevertheless, it is important for all New Yorkers -- electric power generators, drivers, homeowners, communities, businesses, industries and institutions -- to reduce greenhouse gas emissions. Through greenhouse gas mitigation programs, New York State seeks to help and encourage all sectors to save energy and produce less greenhouse gas.
To view greenhouse gas data in New York and other states, EPA has made a "transparent, powerful data resource available to the public." This program can be viewed by visiting the EPA link on right. Users can also search for data on specific facilities or regions. The list contains emission data from power plants, oil refineries, paper mills and other industries [but does not include all US GHG emissions].
Climate Change Impacts in New York
Scientific evidence says that the earth's climate is changing. New York is experiencing this change in numerous ways, including:
- Average temperatures in the state are 1.8 degrees Fahrenheit higher than they were as recently as 1970.
- Winter temperatures are 4.4 degrees higher than in 1970.
- Plants in New York now bloom as much as 8 days earlier in the spring than they did in 1970.
- Birds that traditionally breed in New York have moved their ranges northward by as much as 40 miles in the past two decades.
- Diseases from the tropics, such as West Nile disease and Lyme disease, are appearing further north.
Earlier springs threaten maple syrup production
and other traditional New York agricultural enterprises.
Scientists predict that New York could see additional impacts as the planet's climate warms. These include:
- Additional warming, estimated at 2 to 3 degrees Fahrenheit, because of greenhouse gases already in the atmosphere.
- Dry spells of several weeks' duration, punctuated by extreme rains and storms.
- Winter snow cover reduced enough to affect the recreation industry.
- Loss of cool-weather plants and animals that have traditionally lived in New York, such as sugar maples and some marine species.
- Sea levels rising by between 4 inches and 33 inches (or even more if the earth's large ice sheets are destabilized). The amount of sea level rise will depend on how successfully, and how soon, nations are able to reduce greenhouse gas emissions.
To help all New Yorkers adapt to impacts of climate change that cannot be avoided, New York State is initiating climate adaptation programs.
See the Climate Change Information Resources page for websites that provide details about climate science and the projected impacts of climate change. For additional information on Climate Change impacts, Cornell University has prepared a series of fact sheets available on Cornell's Climate Change website (see link on right).