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Climate Change Science:�Consequences of Warming: Physical Climate

Richard B. Rood

August 2020

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Starting point: A fundamental conclusion

Based on the scientific foundation of our understanding of the Earth’s climate, we predict with virtual certainty

The average global temperature of the Earth’s surface will continue to rise
Historically stable masses of ice on land will melt.
Sea level will rise.
The weather will change.

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Outline:

Consequences of Warming: Physical Climate

Temperature and heat
Ice on land and sea
Sea level rise
Weather change

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Temperature and heat

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Ocean Heat Content

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Last month that was below the 20^th century average: February 1985

Each of last four decades warmer than all previous decades.

We are, today, ~ 1 degree C warmer, globally, than pre-industrial (1750 base)
There are many regions where we are above 2 degrees C

When were you born?
Median age of world is ~ 31 years.

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Temperature (~Traverse City)

1950s

1960s

1970s

1990s

2000s

2010s

1980s

30-year Averaging Period

Michigan Climate Division # 3:

Northwest Lower Peninsula

Each of last three decades warmer than previous decades.

Spread of Averaging Period

Directional (Up)

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Mean January Temperatures

Traverse City, MI 1951-1980 vs 1981-2010

1951 - 1980

1981 - 2010

Average T has increased from 19.7 F to 22.1 F

Number of warmer days increases

Occasionally, still gets cold

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Ice on land and sea

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Muir Glacier, Alaska, in 1941 (left) and 2004 (right).

Muir Glacier, Alaska, in 1880 (left) and 2005 (right).

Thanks to Paul Edwards

Top left photo: Hazard, G.D. 1880. Muir Glacier: From the Glacier photograph collection. Boulder, Colorado USA: National Snow and Ice Data Center/World Data Center for Glaciology. Digital media.

Top right photo: Molnia, Bruce F. 2005. Muir Glacier: From the Glacier photograph collection. Boulder, Colorado USA: National Snow and Ice Data Center/World Data Center for Glaciology. Digital media.

Bottom left photo: Field, William O. 1941. Muir Glacier: From the Glacier photograph collection. Boulder, Colorado USA: National Snow and Ice Data Center/World Data Center for Glaciology. Digital media.

Bottom right photo: Molnia, Bruce F. 2004. Muir Glacier: From the Glacier photograph collection. Boulder, Colorado USA: National Snow and Ice Data Center/World Data Center for Glaciology. Digital media.

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Glacier & ice sheet mass loss

Climate Science Special Report (2017)

Caption: Time series of the cumulative climatic mass balance (units: kg/m²) in five arctic regions and for the Pan-Arctic from the World Glacier Monitoring Service (WGMS; Wolken et al.; solid lines, left y-axis), plus Alaskan glacial mass loss observed from NASA GRACE (dashed blue line, right y-axis). (Figure source: Harig and Simons 2016 and Wolken et al. 2016;⁵ © American Meteorological Society, used with permission.)

https://science2017.globalchange.gov/chapter/11/

This panel, “Glacier Mass Loss”, is an adapted figure provided by Patrick Taylor. Please contact this person for any questions or additional information regarding this figure.

The figure version presented here was adapted from the original as follows:

In two previous publications, the time series for climatic mass loss from Alaskan glaciers has been published. One is Fig. 5.13 from the State of the Climate 2015 report (yellow line) and another, shorter record from NASA GRACE data (Harig and Simons 2016). These were combined onto a single plot.

The original figure is found in:

Harig, C., and F. J. Simons (2016),Ice mass loss in Greenland, theGulf of Alaska, and the CanadianArchipelago: Seasonal cycles anddecadal trends, Geophys. Res. Lett.,43, 3150–3159,doi:10.1002/2016GL067759 Wolken, G. and coauthors, 2016: Glaciers and ice caps outside Greenland [in "State of the Climate in 2015"]. Bull. Amer. Meteor. Soc, 97, (8), S142-S145.

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Larsen B Ice Shelf collapse

January 31, 2002

March 5, 2002

From NASA: Animation at this link

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Arctic sea ice decline

Climate Science Special Report (2017)

Caption: September sea ice extent and age shown for (a) 1984 and (b) 2016, illustrating significant reductions in sea ice extent and age (thickness). Bar graph in the lower right of each panel illustrates the sea ice area (unit: million km²) covered within each age category (>1 year), and the green bars represent the maximum value for each age range during the record. The year 1984 is representative of September sea ice characteristics during the 1980s. The years 1984 and 2016 are selected as endpoints in the time series; a movie of the complete time series is available at http://svs.gsfc.nasa.gov. (c) Shows the satellite-era arctic sea ice areal extent trend from 1979 to 2016 for September (unit: million mi²). [Figure source: Panels (a),(b): NASA Science Visualization Studio; data: Tschudi et al. 2016; Panel (c) data: Fetterer et al. 2016 ]

NASA's Scientific Visualization Studio (svs.gsfc.nasa.gov/4489) Tschudi, M., C. Fowler, J. Maslanik, J. S. Stewart, and W. Meier. 2016. EASE-Grid Sea Ice Age, Version 3. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: http://dx.doi.org/10.5067/PFSVFZA9Y85G. [10/28/2016]

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Sea level rise

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Sea level rise

High Emissions (RCP 8.5)

Low Emissions (RCP 2.6)

(Close to 2°C Goal)

Likely an underestimate

Continues on for centuries

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Tidal / nuisance flooding

Climate Science Special Report (2017)

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Weather will change

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Extreme precipitation events in U.S.�(1958 – 2012)

National Climate Assessment (2014)

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Precipitation Extreme Events in U.S. Through 2016

Climate Science Special Report (2017)

Caption: Index of the number of 2-day precipitation events exceeding the station-specific threshold for a 5-year recurrence interval in the contiguous United States, expressed as a percentage difference from the 1901–1960 mean. The annual values are averaged over 5-year periods, with the pentad label indicating the ending year of the period. Annual time series of the number of events are first calculated at individual stations. Next, the grid box time series are calculated as the average of all stations in the grid box. Finally, a national time series is calculated as the average of the grid box time series. Data source: GHCN-Daily. (Figure source: CICS-NC and NOAA NCEI).

https://science2017.globalchange.gov/chapter/7/

A U.S. index of extreme precipitation from NCA3 was updated (Figure 7.3) through 2016. This is the number of 2-day precipitation events exceeding the threshold for a 5-year recurrence. The values were calculated by first arithmetically averaging the station data for all stations within each 1° by 1° latitude/longitude grid for each year and then averaging over the grid values across the contiguous United States for each year during the period of 1896–2015. The number of events has been well above average for the last three decades. The slight drop from 2006–2010 to 2011–2016 reflects a below-average number during the widespread severe meteorological drought year of 2012, while the other years in this pentad were well above average. The index value for 2015 was 80% above the 1901–1960 reference period average and the third highest value in the 120 years of record (after 1998 and 2008).

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Summary: Consequences of Warming: Physical Climate

We have observational evidence of increase in temperature and accumulation of heat in the environment.

This will continue for decades.
We need to intervene and reduce carbon dioxide emissions and concentrations in the atmosphere to limit this warming.

This lecture is only a glimpse.

Many other variables in physical climate
Many changes in the biological activity of Earth

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Resources and Recommended Reading

National Climate Assessment 2014

https://nca2014.globalchange.gov/report

Climate Science Special Report 2017

https://science2017.globalchange.gov/

National Climate Assessment 2018

https://nca2018.globalchange.gov/

Annual State of the Climate

https://www.ametsoc.org/index.cfm/ams/publications/bulletin-of-the-american-meteorological-society-bams/state-of-the-climate/

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