Climate & Climate Change

Ch. 21

Part 2

• Here’s what you researched & presented as a evidence to support the statement that climate is changing…1. snow & ice coverage (sea ice, ice sheets… Antarctica & Greenland,

alpine/mountain glaciers) 2. atmospheric (air) temperature3. sea-surface temperature & sea-level change4. extreme/more intense weather events (droughts, floods, blizzards,

hurricanes, etc.)5. species health (ex. coral bleaching, extinctions, polar bear starvation),

skeletal/shell composition in marine organisms 6. species distribution/range (mosquitoes/insects, birds, crop locations)7. phenological trends (ex. timing of bud-burst/plant blossoming, leaf fall,

migration patterns/timing, hibernation patterns, crop growing-seasons)8. ice core data9. tree ring data

Evidence for Climate Change

Possible Effects of Climate Change

• recreation loss• skiing• snowboarding

• decreased river flow• salmon

declines• hydropower

loss• drinking

water shortages

Possible Effects of Climate Change

• decreased recharge– lower

ground water tables

Possible Effects of Climate Change

•decreased planetary albedo

Possible Effects of Climate Change

• changes in ocean conveyor belt• thermo-haline circulation

Possible Effects of Climate Change

• affects to indigenous peoples•Hunting• transportation

Possible Effects of Climate Change

• decrease in:‒ resting and birthing place for seals and walrus‒ hunting and breeding grounds for polar bears‒ foraging grounds for arctic fox, whales, caribou, &

other mammals

Possible Effects of Climate Change

• coastal flooding– destruction of wetlands– damage to towns/cities

• coastal erosion

Possible Effects of Climate Change

• droughts– crop losses– Increased forest

fires– flooding when it

finally does rain• due to soil

hardening increasing the amount of runoff

Possible Effects of Climate Change

• floods– more landslides– more runoff• more pollution

Possible Effects of Climate Change

• economic losses

Possible Effects of Climate Change

Projecting Climate In the Future

• climate models– computer

programs that use past & current data to:• project what

future climate might be like• figure out why

climate is changing

http://edgcm.columbia.edu/

The IPCC

The IPCC http://www.ipcc.ch/

2007 Conclusions

• Warming of the climate system is unmistakable

• Very high confidence that the effect of human activities since 1750 is one of warming

• Human-caused warming over last 30 years has likely had a visible influence on many physical and biological systems

• Continued GHG emissions at or above current rates would cause further warming and induce many changes in the global climate system during the 21st century that would very likely be larger than those observed during the 20th century.”

http://www.ipcc.ch/

Consensus?

• Do we know enough about the drivers of climate to know what causes change?

• Are we underestimating the Earth system’s complexity?

• Can models accurately simulate the complex climate system?

•Are there processes that will limit warming naturally?

On the other hand…

• Arctic sea ice melting faster than predicted.

• Fossil fuel emissions exceeded most IPCC projections.

• Are assumptions about global energy use are too optimistic?

• How quickly can developing countries reduce GHG emissions?

• Calculations don’t include unexpected melting in Greenland and Antarctica.

What next? What can we do?

What next? What can we do?Billions of tons of carbon emitted per year

Produce more fuel-efficient vehicles.Reduce vehicle use.Improve energy-efficiency in buildings.Develop carbon capture and storage processes.Triple nuclear power.Increase solar power.Decrease deforestation/plant forests.Improve soil carbon management strategies .

What next? What can we do?

Some Individual Actions…

Use mass transit, bike, walk, roller

skate

Tune up your

furnace

Unplug appliances or plug into a

power strip and switch it off

Buy water-saving appliances and

toilets; installing low-flow shower

heads.

Caulk, weather-strip, insulate, and replace old windows

Buy products with a U.S. EPA

Energy Star label