global warming: temperature and precipitation observations and predictions
DESCRIPTION
Global warming: temperature and precipitation observations and predictions. Methods to establish human influence. Climate observations Climate modeling Simulation of how climate will change Run forward to make predictions of the future Run backwards Run without carbon dioxide increase - PowerPoint PPT PresentationTRANSCRIPT
![Page 1: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/1.jpg)
Global warming: temperature and precipitation observations and predictions
![Page 2: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/2.jpg)
Methods to establish human influence
• Climate observations• Climate modeling
– Simulation of how climate will change– Run forward to make predictions of the future– Run backwards
• Run without carbon dioxide increase• Run with carbon dioxide increase• Compare output to see which more accurately predicts
observations
– Must also take into account changes in emissions scenarios
![Page 3: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/3.jpg)
Finite difference technique of weather and climate forecasting (Richardson, 1922)
![Page 4: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/4.jpg)
Global climate models
![Page 5: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/5.jpg)
1900 1950 2000Year
Tem
pera
ture
ano
mal
y 1
0.5
0
Models using only natural forcing
Models using both natural and anthropogenic forcing
Observations
Global temperature change
![Page 6: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/6.jpg)
Emissions scenarios
![Page 7: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/7.jpg)
Best estimate and likely
uncertainty range at 2100
Model predictions based on emissions scenarios
![Page 8: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/8.jpg)
IPCC: Intergovernmental Panel on Climate Change
• Established by:• World Meteorological Organization (WMO) • United Nations Environment Programme (UNEP)
• Open to all member governments of the UN and WMO• Started in 1988 - Full reports in 1990, 1995, 2001, 2007• IPCC statement on their role:
– “The role of the IPCC is to assess on a comprehensive, objective, open and transparent basis the scientific, technical and socio-economic information relevant to understanding the scientific basis of risk of human-induced climate change, its potential impacts and options for adaptation and mitigation.”
![Page 9: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/9.jpg)
IPCC
• Every 5-6 years, over 1000 scientists from more than 100 nations assess the published scientific literature documenting the state of scientific knowledge related to climate change issues. The IPCC reports are ratified by the ~180 member nations.
• The IPCC does not conduct the research, they review it and make a consensus statement based on membership
![Page 10: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/10.jpg)
![Page 11: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/11.jpg)
IPCC statements
• First Assessment Report (1990): “The size of the warming over the last century is broadly consistent with the prediction by climate models, but is also of the same magnitude as natural climate variability . Thus the observed increase could be largely due to this natural variability: alternatively this variability and other human factors could have offset a still larger human-induced greenhouse warming. The unequivocal detection of the enhanced greenhouse effect from observations is not likely for a decade or more.
![Page 12: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/12.jpg)
IPCC statements
• Second Assessment Report (1995): “The balance of evidence suggests a discernible human influence on global climate.”
![Page 13: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/13.jpg)
IPCC statements
• Third Assessment Report (2001): “There is new and stronger evidence that most of the warming observed over the last 50 years is attributable to human activities.”
![Page 14: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/14.jpg)
IPCC statements
• Fourth Assessment Report (2007): “Most of the observed increase in global average temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.”
![Page 15: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/15.jpg)
Fourth Assessment Report, 2007
• Very high confidence that the globally averaged net effect of human activities since 1750 has been one of warming, with a radiative forcing of +1.6 [+0.6 to +2.4] watts per m-2.
• For the next two decades a warming of about 0.2°C (0.4°F) per decade is projected for a range of emission scenarios.
![Page 16: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/16.jpg)
![Page 17: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/17.jpg)
![Page 18: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/18.jpg)
![Page 19: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/19.jpg)
1979-2003
1951-1978
1901-1950
Number of nights
![Page 20: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/20.jpg)
Heat waves have become more frequent over most land areas
- Heat wave in Europe, 2003: 35 000 deathsHeat waves have become more frequent over most land areas.
![Page 21: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/21.jpg)
![Page 22: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/22.jpg)
![Page 23: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/23.jpg)
![Page 24: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/24.jpg)
![Page 25: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/25.jpg)
The frequency of heavy precipitation events has increased over most land areas. Flooding in Bangkok, Thailand in 2011
![Page 26: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/26.jpg)
Phot
o cr
edit:
Goo
dPla
net
More intense and longer droughts have been observed over wider areas since the 1970s, particularly in the tropics and subtropics
![Page 27: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/27.jpg)
![Page 28: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/28.jpg)
![Page 29: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/29.jpg)
![Page 30: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/30.jpg)
![Page 31: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/31.jpg)
![Page 32: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/32.jpg)
![Page 33: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/33.jpg)
![Page 34: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/34.jpg)
Feedbacks
• Positive feedbacks – a system of interactions that reinforces the initial inputs or their effects; snowball effect
• Negative feedback – a system of interactions that limits or keeps in check the initial inputs or its effect
![Page 35: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/35.jpg)
![Page 36: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/36.jpg)
![Page 37: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/37.jpg)
Regional versus global scale models
• Difficult to make predictions at finer scales that involve policy– Global models: 150 km resolution or grid cell size– Regional models: 25 km resolution or grid cell size
• Nested models
![Page 38: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/38.jpg)
Regional versus global scale models
• Criticism of regional models is that they may have high precision but lower accuracy
![Page 39: Global warming: temperature and precipitation observations and predictions](https://reader036.vdocument.in/reader036/viewer/2022062520/5681570d550346895dc4af52/html5/thumbnails/39.jpg)