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Climate Change 101


The term greenhouse is derived from the glass houses people build to trap heat inside to create a warm environment in which to grow food. The Earth’s atmosphere, much like a greenhouse, traps heat, but in a different way. Gases high in the atmosphere, such as carbon dioxide (CO2) behave like a giant piece of curved glass wrapped around the planet. The Sun’s rays pass straight through the carbon dioxide, a greenhouse gas, and warm up the Earth. The warming planet gives off heat energy which radiates out toward space. Some of this outgoing radiation does not pass through the atmosphere, but is reflected back down to Earth, effectively trapping heat and keeping the planet warm enough for life to exist. This is called the natural greenhouse effect, and it’s a good thing.












The greenhouse effect would be nothing to worry about were it not for one important thing. Since the industrial revolution started in the 1800s, humans have been burning large quantities of coal, oil, and other fossil fuels primarily to generate energy and later fuel transportation. When burned, fossil fuels release carbon dioxide (CO2) into the atmosphere. As humans burn large quantities of fossil fuels we are increasingly heating up the atmosphere via a phenomena called  “the greenhouse effect”. The carbon dioxide (CO2) drifts up into the atmosphere and makes Earth’s greenhouse gas just a little thicker. This is called the enhanced greenhouse effect. As a result, more of the Sun’s heat gets trapped inside the atmosphere and the planet warms up more than it should.

Because of all the fossil fuels humans are burning, there is now more carbon dioxide (CO2) in the atmosphere (as of April 2017 we reached 410 parts per million).  Carbon dioxide hasn’t reached this height in millions of years. It’s a new atmosphere that humanity will have to contend with, one that’s trapping more heat and causing the climate to change at a quickening rate.

This burning of fossil fuels and subsequent releasing of CO2 into the atmosphere is fueling climate change.

Currently, 80% of the world’s energy comes from fossil fuels. There are other man-made sources of greenhouse gases – CO2 from burning fossil fuels is simply the largest source. The amount of energy people use is increasing too. Unless humans change things, the amount of carbon dioxide (CO2) in the atmosphere will continue to increase—and the Earth will continue to heat up and global warming will get worse.

More information on the greenhouse effect from the Intergovernmental Panel on Climate Change.


“The Greenhouse Effect” in: “Introduction,” in: US EPA (December 2012) Climate Change Indicators in the United States, 2nd edition[1], Washington, DC, USA: US EPA, p.3. EPA 430-R-12-004.

HWLG 101

What is Sea Level Rise?

As the Earth warms up, the oceans warm up too—very slowly but significantly. Water expands as it warms. As the oceans are heated, the water they contain takes up more volume, causing the level of the seas to rise. The seas also rise when ice sheets and land based glaciers melt due to warmer temperatures, feeding more water into the oceans. As of early 2017, the National Oceanic and Atmospheric Administration projects sea levels will rise another one to eight feet by 2100.

Sea-level rise is one of the major impacts of global warming. Entire low lying countries like Bangladesh, or low-lying islands are also vulnerable to sea level rise. Sea level rise means the ocean will gradually inundate low-lying areas and storms like hurricanes, bolstered by even higher seas, will extend their reach inland.

Since the industrial revolution, global sea levels have already risen by about 8 inches, in some regions, due to a series of local factors the rise is even higher. Scientists agree that sea level will continue to rise. What that means for a particular area depends largely on local factors. Since over half of the world’s people live in regions vulnerable to sea level rise, preparing for this global change is something we all can do simultaneously.

Can We Stop Sea Level Rise?

In the short term, no. Because people have been burning fossil fuels since the industrial revolution, CO2 is already in our atmosphere. These gases can remain in the atmosphere for hundreds of years before being removed by natural processes. The warming influence of CO2s will go into the next century. Unfortunately we can’t halt the sea level rise that will occur in the next 50-100 years. However we can reduce our carbon emissions to help future generations. The choices we make today will determine how rapidly sea level rise accelerates, as well as whether communities are sufficiently prepared to adapt.


The view from aerial tour of Hurricane Sandy damage of New Jersey’s barrier beaches, Nov. 18, 2012.
(Official White House Photo by Sonya N. Hebert)

HWLG Impacts

Climate Change Impacts

Sea Level Rise
HighWaterLine _ Bristol_ St Werburghs.jpg

Hurricanes & Extreme Storms

While hurricanes are a natural part of our climate system, recent research suggests that their destructive power, or intensity, has been growing since the 1970s, particularly in the North Atlantic region. Since the mid-1970s, the number of hurricanes that reach Categories 4 and 5 in strength—the two strongest classifications—has roughly doubled.

Warm ocean temperatures are one of the key factors that strengthen hurricane development when conditions are conducive to their formation and growth. Therefore, as the climate continues to warm the frequency of intense hurricanes in the North Atlantic is projected to rise. An ever growing number of people and structures are at risk from the destructive potential of hurricanes.

Storm Surge

Storm surge created by hurricanes is the biggest risk to life and property during a storm. Storm surge happens along the coastline when hurricane winds or the winds from an extreme storm push water towards the coast. The surge intensity depends on many factors including storm strength, speed, angle of approach, the topography of the land and tides.

Higher sea levels give coastal storm surges a higher starting point when major storms approach, launching water up along the shore. The resulting storm surge reaches higher and penetrates further inland in low-lying areas. The risk is even greater if storms make landfall during high tides.

For more information: Union of Concerned Scientists, Hurricanes and Climate Change


Extreme Rainfall

Climate change creates warmer air which is capable of containing more water vapor than cooler air. When this air becomes a storm, it produces more precipitation. Extreme rainfall often leads to extreme flooding.

By U.S. Army photo by 1st Lt. Zachary West [Public domain], via Wikimedia Commons

The most extreme climate impacts predicted in Europe are an increased likelihood of extreme rainfall events and overall increased rainfall (Northern Europe) (IPCC 5th Assessment Report, Europe, p2175). The UK is set to see about a 10% rise in annual average rainfall by 2100 (IPPC 5th Assessment Report, Summary for Policymakers p20). This coupled with climate change’s effect on the direction of jet streams, means that the UK is starting to get exposed to sequences of storms and heavy downpours which provide the conditions for ongoing increased instances of flooding (Met Office, Report: The Recent Storms and Floods in the UK, 2014).


Learning if you live in a potential flood zone and preparing yourself, your friends, and family as well as your community for the next flood, will save lives as well as decrease damage to your home and greater community.


Frequent Flooding

Climate change and it’s subsequent sea level rise, stronger storms and more extreme storms all add up to more frequent flooding for many coastal cities. This inundation of water creates chronic problems for homes and a city’s infrastructure.


So-called “nuisance flooding” has increased in coastal communities, flooding occurs now with most high tides, overwhelming stormwater infrastructure and leaving entire neighborhoods damaged,  and city infrastructure crippled. The term “nuisance” belies the major disruption this causes on lives and livelihoods. Repeated and frequent floods also cause stress and health issues from recurrent problems like mold and encountering waters containing toxins.

Higher sea levels give coastal storm surges a higher starting point when major storms approach, launching water up along the shore. The resulting storm surge reaches higher and penetrates further inland in low-lying areas. The risk is even greater if storms make landfall during high tides.

For more information: Union of Concerned Scientists, Hurricanes and Climate Change


Additional Resources


NASA Global Climate Change – “The mission of “Global Climate Change: Vital Signs of the Planet” is to provide the public with accurate and timely news and information about Earth’s changing climate, along with current data and visualizations, presented from the unique perspective of NASA, one of the world’s leading climate research agencies.”

NOAA – “NOAA provides timely and authoritative information about climate. We promote public understanding of climate science and climate-related events through videos, stories, images, and data visualizations; we make common data products and services easy to access and use; and we provide tools and resources that help people make informed decisions about climate risks, vulnerability, and resilience.”

International Panel on Climate Change – “The Intergovernmental Panel on Climate Change (IPCC) is the international body for assessing the science related to climate change. The IPCC was set up in 1988 by the World Meteorological Organization (WMO) and United Nations Environment Programme (UNEP) to provide policymakers with regular assessments of the scientific basis of climate change, its impacts and future risks, and options for adaptation and mitigation.”

Climate Central – “An independent organization of leading scientists and journalists researching and reporting the facts about our changing climate and its impact on the American public.”

START – “START promotes research-driven capacity building to advance knowledge on global environmental change in Africa and Asia-Pacific.”

Environment Agency – “We work to create better places for people and wildlife, and support sustainable development. EA is an executive non-departmental public body, sponsored by the Department for Environment, Food & Rural Affairs.”


The Alliance for Climate Education (a U.S. based organization) has a wealth of free resources and activities for teachers.

NASA Climate Change Resources for Educators

NOAA Teaching Climate

Teach Climate from Climate UK


FEMA Flood Maps for the United States

Environment Agency Flood Maps for the UK

European Commission Flood Mapping

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