Global climate change
This presentation is the property of its rightful owner.
Sponsored Links
1 / 24

Global Climate Change PowerPoint PPT Presentation


  • 77 Views
  • Uploaded on
  • Presentation posted in: General

Global Climate Change. The Greenhouse Effect. Some of the infrared radiation passes through the atmosphere, and some is absorbed and re-emitted in all directions by greenhouse gas molecules. The effect of this is to warm the Earth’s surface and the lower atmosphere.

Download Presentation

Global Climate Change

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Global climate change

Global Climate Change


Global climate change

The

Greenhouse Effect

Some of the infrared radiation

passes through the atmosphere,

and some is absorbed and

re-emitted in all

directions by

greenhouse gas

molecules. The

effect of this

is to warm

the Earth’s

surface and

the lower

atmosphere.

Some solar radiation

is reflected by the

Earth and the

atmosphere

Solar

radiation

passes

through

the clear

atmosphere

Infrared radiation is emitted

from the Earth’s Surface

Most radiation is absorbed by the

Earth’s surface and warms it


Global climate change

Greenhouse Gases (GHG)

Carbon dioxide*

Methane* - CH4

Nitrous oxide* - N2O

CFCs – chlorofluorocarbons**

Water vapor

*These are increasing due to human activities, primarily burning of fossil fuels

** Being phased out, but persist in the atmosphere for decades


Global climate change

2

SO4

NO3

Primary Pollutants

CO

CO2

Secondary Pollutants

SO2

NO

NO2

SO3

Most hydrocarbons

HNO3

H2SO4

Most suspended

particles

H2O2

O3

PANs

Most

and

salts

Sources

Natural

Stationary

Mobile


Examples of greenhouse gases affected by human activities

Examples of Greenhouse Gases Affected by Human Activities

CO2 CH4 N2O

Pre-industrial concentration288 ppmv848 ppbv285 ppbv

Concentration in 1999366 ppmv1800 ppbv312 ppbv

100 year Global Warming Potential121310

Atmospheric lifetime (years)50-200a12b120

ppmv = part per million volume; ppbv = part per billion volume

a No single lifetime for CO2 can be defined because of the different rates of uptake by different processes.

b Defined as an adjustment time which takes into account the indirect effects of methane on its own lifetime.

Sources: IPCC 1995, CDIAC (Manua Loa, Siple Station, Law Dome “DE08”, AGAGE, and

Law Dome “BHD” data)


Global climate change

Atmospheric carbon dioxide does vary over time -Graph below shows earth’s atmospheric CO2 levels back 400,000 years before present based on ice core data


Global climate change

380

380

360

360

340

CO2 Concentration (ppmv)

340

320

300

CO2 Concentration (ppmv)

320

280

1850

1900

1950

2000

300

280

260

800

1000

1200

1400

1600

1800

2000

Year

CO2 Concentrations Over the

Past 1000 Years

Source: Based on IPCC (1994)


Atmospheric carbon dioxide levels 1960 2000

Atmospheric carbon dioxide levels 1960-2000

Graph interpretation:

  • What is happening to the level of carbon dioxide in the atmosphere?

  • What accounts for the rise and fall within each year?


Current levels of atmospheric co2

Current levels of atmospheric CO2

January 2011: 391ppm

“Safe” level is 350ppm or less

Has been over 350 since 1988

http://co2now.org/


Global climate change

Global Warming?

  • This graph shows annual mean global temperature anomalies over the period 1880-2001. The zero line represents the long term mean temperature from 1880-2001, and the red and blue bars are showing annual departures from that mean. As is evident in the graph, 2001 was second only to 1998 in terms of global temperature, and the trend has been toward increasing temperatures at least since the beginning of the 20th century. Land temperatures have greater anomalies than the ocean, which is to be expected since land heats up and cools down faster than water.


Consequences of global warming

Consequences of global warming

  • Rising sea levels – due to (1) melting of glaciers and polar ice (documented already)

    (2) thermal expansion of ocean at warmer temps

    How will this affect polar regions? Islands? Coastal cities?


Documented sea level rise from 1880 2000

Documented sea level rise from 1880-2000


Effects of a 1m rise in sea level

Effects of a 1m rise in sea level


Global climate change

2. Human health problems

  • More problems with mosquitoes, diseases they transmit

  • Ground-level ozone increases, leading to breathing problems


Global climate change

HEALTH EFFECTS OF CLIMATE CHANGE

Heat Stress

Cardiorespiratory failure

Respiratory diseases, e.g., COPD & Asthma

Malaria

Dengue

Encephalitis

Hantavirus

Rift Valley Fever

Cholera

Cyclospora

Cryptosporidiosis

Campylobacter

Leptospirosis

Malnutrition

Diarrhea

Toxic Red Tides

Forced Migration

Overcrowding

Infectious diseases

Human Conflicts

Urban Heat Island Effect

Air Pollution

Vector-borne Diseases

Water-borne Diseases

Water resources & food supply

Environmental Refugees

CLIMATE

CHANGE

Temperature Rise 1

(Sea level Rise 2)

Hydrologic Extremes

12°C by yr. 2100

249 cm“ “

IPCC estimates

Source: Jonathan Patz, 1998


Consequences of global warming1

Consequences of global warming

3. Changes in weather patterns, such as more severe storms, changes in precipitation

The frequency of downpours and heat waves, as well as the power of hurricanes, has increased so dramatically that "100-year storms" are striking some areas once every 15 years


Consequences of global warming2

Consequences of global warming

4. Agriculture

Decrease in crop yield due to drought, floods

Increased need for irrigation


Consequences of global warming3

Consequences of global warming

5. Effects on plants and animals

Organisms in ecosystems are adapted for certain climate and if that changes, plants and animals there may not survive (adaptation in plants and animals takes time and global warming is changing things quickly), ex: polar bear

Models predicting future status

of polar bears are debated

(models are, by nature, complex)


Global climate change

Present Range

Overlap

Predicted Range

Current and Projected Ranges of Sugar Maple

Prediction based on increased

temperature

Prediction based on increased

temperature and moisture reduction

Source: Redrawn from Davis and Zabinski, 1992


Debate over global warming

Debate over global warming?

IPCC –

  • Intergovernmental Panel on Climate Change

  • Established to be an objective source of information on climate change for policy makers worldwide

  • made conclusions based on many scientific studies

  • concluded with statistical certainty (90%) that human activity is contributing to global warming, 2007

    See their report:

    http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf


Nobel peace prize

Nobel Peace Prize

Nobel Peace Prize was awarded in 2007 to Al Gore, former Vice President of U.S., and the IPCC for work on the issue of climate change

What does global warming have to do with world peace?


Kyoto protocol 1997

Kyoto Protocol, 1997

International agreement to reduce greenhouse gas emissions

About 120 countries agreed, U.S. has not

U.S. objections: negative economic impacts, developing countries not held to same protocol as developed countries (not seen as fair)

Expires in 2012


Copenhagen accord 2009

Copenhagen Accord, 2009

U.N. sponsors a yearly meeting of many of the world’s countries to discuss global climate change

Recent outcome: Copenhagen Accord – non-binding agreement to combat climate change

Some of the main points:

  • Recognizes the scientific view that an increase of 2°C should be the limit in order to combat climate change

  • Countries set goals to reduce GHG emissions

  • Reduction in deforestation is critical

  • Endorsed continuation of Kyoto Protocol

  • Funding/incentives should be provided to

    developing countries


Copenhagen accord 20091

Copenhagen Accord, 2009

Criticism

  • Not a legal agreement

  • Was drafted by only 5 countries

  • Does not say where funding will come from

  • Sets no real targets for emissions reductions

  • Countries only “took note” of the accord, did not adopt it


  • Login