Global Environmental Change

Climate Change, Global Warming…

…what’s going on?

What is Climate?• Climate = the average and variations of

weather over a long period of time (~30 years)

Above: Global average for atmospheric water vapor.

What is Weather?

• Weather = all natural phenonmena within the atmosphere at a given time (hours to days)

• The Earth has many different systems that interact with each other in different ways.

LandLand

OceansOceans AtmosphereAtmosphere

BiosphereBiosphere

IceIce

The Climate System

Modern Climate Systems

• Atmospheric circulation

Sunlight

Modern Climate Systems

• Atmospheric circulation

H.C.

F.C.P.C.

Modern Climate Systems

• Ocean circulation

The Great Ocean Conveyor

Sinking cool water, rising warm water and wind help to form global ocean current systems.

• Atmosphere and Greenhouse Effect– The Earth’s atmosphere keeps it around

30°C warmer than it would otherwise be.– This is the Greenhouse Effect

Modern Climate Systems

What is the Greenhouse Effect?

cc. Robert A. Rohde (Global Warming Art)

cc. Robert A. Rohde (Global Warming Art)

The temperature of the Earth depends on the amount of energy we receive from the sun versus the amount of energy lost back out to space.

The Carbon Cycle

Past Climate Systems

• How do we know about climate systems in the past?

Past Climate Systems

1. Early human record

Tourism NT http://www.travelnt.com

Rock paintings provide evidence of fertile Sahara region (now desert) 6,000 years ago.

cc. W.V. Bailey

Past Climate Systems

2. Geomorphology

Above: A “U” shaped valley shows that it was formed by a glacier.

River deltas show where rivers entered the ocean or a lake.

Past Climate Systems

3. Geological record

Drilling into the ground can recover rock layers that record what conditions were like when the rock was deposited.

Fossils preserve evidence of past life.

Past Climate Systems

4. Ice cores

GISP2 ice core at 1837m depth with clearly visible annual layers.

Ice cores can preserve seasonal layering. Studying the chemistry of each layer can give clues about climate change.

Is the Climate Changing?

https://www.ted.com/talks/gavin_schmidt_the_emergent_patterns_of_climate_change

What is Climate Change?

• The variation in the Earth's global climate or in regional climates over time.

What are the current climate trends?

cc. Robert A. Rohde http://www.globalwarmingart.com/wiki/Image:Instrumental_Temperature_Record_png

Global temperature for the last 150 years

What are the current climate trends?

cc. Robert A. Rohde http://www.globalwarmingart.com/wiki/Image:Global_Warming_Map_jpg

Looking further into the past…

cc. Robert A. Rohde http://www.globalwarmingart.com/wiki/Image:1000_Year_Temperature_Comparison_png

Global temperature for the last 1000 years

Looking further into the past…

cc. Robert A. Rohde http://www.globalwarmingart.com/wiki/Image:Ice_Age_Temperature_Rev_png

Global temperature for the last 450,000 years

Anthropogenic Influence

• Fossil fuel

• Aerosols

• Cement manufacture

• Land use

• Livestockcc. Robert A. Rohde http://www.globalwarmingart.com/wiki/Image:Carbon_Dioxide_400kyr.png

Fossil Fuels:• Beginning with the industrial revolution in the 1850s

and accelerating ever since, the human consumption of fossil fuels has elevated CO2 levels from a concentration of ~280 ppm (parts per million) in the atmosphere to more than 380 ppm today.

• These increases are projected to reach more than 560 ppm before the end of the 21st century. It is known that carbon dioxide levels are substantially higher now than at any time in the last 800,000 years. Along with rising methane levels, these changes are anticipated to cause an increase of 1.4-5.6°C between 1990 and 2100.

Aerosols

• Anthropogenic aerosols, particularly sulphate aerosols from fossil fuel combustion, are believed to exert a cooling influence. This, together with natural variability, is believed to account for the relative "plateau" in the graph of 20th century temperatures in the middle of the century.

Cement Manufacture:

• Cement manufacturing is the third largest cause of man-made carbon dioxide emissions. While fossil fuel combustion and deforestation each produce significantly more carbon dioxide (CO2), cement-making is responsible for approximately 2.5% of total worldwide emissions from industrial sources (energy plus manufacturing sectors).

Land Use:

• Prior to widespread fossil fuel use, humanity's largest effect on local climate is likely to have resulted from land use. For example, irrigation, deforestation, and agriculture change the amount of water going into and out of a given location.

Livestock:• According to a 2006 United Nations report, livestock is responsible

for 18% of the world’s greenhouse gas emissions as measured in CO2 equivalents.

• This however includes land usage change, meaning deforestation in order to create grazing land. In the Amazon, 70% of deforestation is to make way for grazing land, so this is the major factor in the 2006 UN FAO report, which was the first agricultural report to include land usage change into the radiative forcing of livestock. In addition to CO2 emissions, livestock produces 65% of human-induced nitrous oxide (which has 296 times the global warming potential of CO2) and 37% of human-induced methane (which has 23 times the global warming potential of CO2).

Are There Other Causes?• Natural Impacts:

*Volcanoes*Water vapor

*clouds

*Change in sun’s energy output

Milankovitch cycles influence climate• Milankovitch cycles = periodic

changes in Earth’s rotation and orbit around the sun– Alter the way solar radiation is

distributed over Earth• These cycles modify patterns of

atmospheric heating– Triggering climate variation – For example, periods of cold

glaciation and warm interglacial times

Future predictions…

• Based on no changes in emissions (“business as usual”) the Earth would be 3 degrees C hotter on average.

cc. Robert A. Rohde http://www.globalwarmingart.com/wiki/Image:Global_Warming_Predictions_Map_jpg

What does it all mean?

• Sea level rise

• More extreme weather

• Changes in precipitation

• Spread of disease

cc. Robert A. Rohde http://www.globalwarmingart.com/wiki/Image:Recent_Sea_Level_Rise_png

Rising sea levels• Runoff from melting glaciers and ice will cause sea levels to rise • As oceans warm, they expand

– Leading to beach erosion, coastal floods, and intrusion of salt water into aquifers

Projected changes in precipitation

Precipitation will increase at high latitudes and decrease at low and middle latitudes

Coastal areas will flood

• Storm surge = temporary, localized rise in sea level– Caused by the high tides and winds of storms

• Cities will be flooded– 53% of people in the U.S. live in coastal areas

Melting snow and ice• Mountaintop glaciers are disappearing

– Glaciers on tropical mountaintops have disappeared– The remaining 26 of 150 glaciers in Glacier National

Park will be gone by 2020 or 2030– Reducing summertime water supplies

• Melting of Greenland’s Arctic ice sheet is accelerating• Warmer water is melting Antarctic coastal ice shelves

– Interior snow is increasing due to more precipitation• Melting ice exposes darker, less-reflective surfaces, which

absorb more sunlight, causing more melting

Coral reefs are threatened

• Coral reefs are habitat for food fish – Snorkeling and scuba diving sites for tourism

• Warmer waters contribute to coral bleaching– Which kills corals

• Increased CO2 is acidifying the ocean

– Organisms can’t build their exoskeletons• Oceans have already decreased by 0.1 pH unit

– Enough to kill most coral reefs

Climate change affects organisms and ecosystems

• Organisms are adapted to their environments– They are affected when those environments change

• Global warming modifies temperature-dependent phenomena (e.g., timing of migration, breeding)

• Animals and plants will move toward the poles or upward in elevation– 20–30% of species will be threatened with extinction– Rare species will be pushed out of preserves

• Droughts, fire, and disease will decrease plant growth

– Fewer plants means more CO2 in the atmosphere

Climate change affects people• Societies are feeling the impacts of climate change• Agriculture: shortened growing seasons, decreased

production, crops more susceptible to droughts – Increasing hunger

• Forestry: increased fires, invasive species– Insect and disease outbreaks

• Health: heat waves and stress can cause death– Respiratory ailments, expansion of tropical diseases– Disease and sanitation problems from flooding– Drowning from storms

Impacts of climate change will vary

Predictions from two climate models

By 2050, Illinois will have a climate like Missouri’s

By 2090, it will have a climate like Louisiana’s

Causes and consequences of climate change

The FCCC• U.N. Framework Convention on Climate• Change = a plan to reduce greenhouse gas emissions to

1990 levels by 2000 through a voluntary, nation-by-nation approach

• By the late 1990s, it was clear that the voluntary approach would not succeed

• Developing nations created a binding international treaty requiring emission reductions

Intergovernmental Panel on Climate Change (IPCC) was established in 1988- Composed of hundreds of international

scientists and government officials

- reports on the synthesis of scientific information concerning climate change

• Global consensus of scientific climate research• Summarized thousands of studies

The IPCC’s fourth assessment report (2007)• Documented observed trends in surface

temperature, precipitation patterns, snow and ice cover, sea levels, storm intensity, etc.

• Predicted impacts of current and future climate change on wildlife, ecosystems, and human societies

• Discussed strategies to pursue in response to climate change

The IPCC’s fourth assessment report (2007)

The Kyoto Protocol tried to limit emissions

• Mandates signatory nations, by the period 2008-2012 , to reduce emissions of six greenhouse gases to levels below those of 1990.

• This treaty took effect in 2005• Russia became the 127th nation to ratify it

• The United States will not ratify the Kyoto Protocol • It requires industrialized nations to reduce emissions• But it does not require industrializing nations (China and India)

to reduce theirs• Other countries resent the U.S. because it emits 20% of the

world’s greenhouse gases but won’t take action• In 2007, one delegate said, “If for some reason you are not

willing to lead...please get out of the way.”

Kyoto Protocol

The Copenhagen Conference • The conference in 2009 tried to design a successor treaty to

the Kyoto Protocol– Nations hoped the U.S., under President Obama, would

participate in a full international agreement• Obama would not promise more than Congress had agreed

to• In a last-minute deal, developed nations will help developing

nations pay for mitigation and adaptation– Nations that reduce deforestation will be rewarded

• Nothing is legally binding and no targets are set

• The largest source of U.S. CO2 emissions

– 70% of electricity comes from fossil fuels– Coal causes 50% of emissions

• To reduce fossil fuel use: – Encourage conservation and efficiency– Switch to cleaner and renewable energy sources

A coal-fired, electricity-generating power plant

Electricity Generation

Conservation and efficiency• We can make lifestyle choices to reduce electricity use

– Use fewer greenhouse-gas-producing appliances– Use electricity more efficiently

• The EPA’s Energy Star Program rates appliances, lights, windows, etc. by their energy efficiency– Replace old appliances with efficient ones– Use compact fluorescent lights– Use efficient windows, ducts, insulation, heating and

cooling systems

Sources of electricity

• We need to switch to clean energy sources– Nuclear power, biomass energy, solar, wind, etc.

• We need to consider how we use fossil fuels– Switching from coal to natural gas cuts emissions 50%– Cogeneration produces fewer emissions

• Carbon capture = removes CO2 from power plant emissions

• Carbon sequestration (storage) = storing carbon underground where it will not seep out– Use depleted oil and gas deposits, salt mines, etc.

– We can’t store enough CO2 to make a difference

• 2nd largest source of U.S. greenhouse gases

– Cars are inefficient

• Ways to help:

– More efficient cars

– Hybrid or electric cars

– Drive less and use public transportation

– Live near your job, so you can bike or walk

U.S. public transportation saves 4.2 billion gallons of gasoline and 37 million metric tons of CO2 emissions

Transportation

Conventional cars are inefficient

We can reduce emissions in other ways

• Agriculture: sustainable land management lets soil store more carbon• Reduce methane emissions from rice and cattle• Grow renewable biofuels

• Forestry: reforest cleared land, preserve existing forests• Sustainable forestry practices

• Waste management: treating wastewater• Generating electricity by incinerating waste• Recovering methane from landfills

• Individuals can recycle, compost, reduce, or reuse goods

Market mechanisms address climate change• Permit trading programs harness the economic efficiency of the free market

to achieve policy goals – Businesses have flexibility in how they meet the goals

• Polluters choose how to cut their emissions– They are given financial incentives to reduce them

Boiling Frog Syndrome

Questions to be answered…

• How fast will the sea level rise?

• How much warmer will it get?

• When will the Arctic Ocean be ice-free?

• Will the water cycle accelerate?

• Are climate extremes increasing?

• Will there be abrupt changes?

Shall we pursue mitigation or adaptation?

• Most people accept that our planet is changing– They are searching for solutions

• Mitigation = pursue actions that reduce greenhouse gas emissions to lessen severity of future climate change– Energy efficiency, renewable energy, protecting soil,

preventing deforestation• Adaptation = accept that climate change is happening

– Pursue strategies to minimize its impacts on us– Seawalls, leaving the area, coping with drought, etc.

• Both are necessary

Science can provide knowledge…

…We all have to provide the solutions.

Climate Change: What can I do?

In your group, write down as many ways to save energy and become “greener” that you can think of. Get one member of each

group to present their ideas.