GEOG 401 Climate Change. Changing Atmosphere Changing Climate

Transcription

1 GEOG 401 Climate Change Changing Atmosphere Changing Climate

2 Changing Atmosphere Greenhouse gases: Water vapor (H2O) Carbon dioxide (CO2) Methane (CH4) Nitrogen dioxide (N2O) Ozone (O3) CFCs Sulfur hexafluoride (SF6) SF6 Figure: hlps://commons.wikimedia.org/w/index.php?curid=697091

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4 Global Warming PotenXal Different gases have different effects on radiaxon absorpxon because of differences in their (a) radiaxve efficiency (ability to absorb LW radiaxon); and (b) lifexme in the atmosphere Global Warming PotenXal (GWP) is the amount of energy absorbed by 1 ton of a gas over a given period (usually 100 years) divided by the energy absorbed by 1 ton of CO2 over the same period.

5 Global Warming PotenXal

6 The Keeling Curve

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8 The Keeling Curve Charles David Keeling at the Mauna Loa Observatory, Hawai i Island

9 Go to the MLO Web Site: hlp://

10 Changing Atmosphere: Carbon Dioxide AR5 WG1 Drae report (2013, Chapter 2)

11 CO2 increase in context

12 Changing Atmosphere: Methane AR5 WG1 Drae report (2013, Chapter 2)

13 Changing Atmosphere: Nitrogen dioxide AR5 WG1 Drae report (2013, Chapter 2)

14 Changing Atmosphere: CFCs, HFCs, etc. AR5 WG1 Drae report (2013, Chapter 2)

15 Changing Atmosphere AR5 WG1 Drae report (2013, Chapter 2)

16 Changing Atmosphere AR5 WG1 Drae report (2013, Chapter 2)

17 Changing Atmosphere Aerosols: Natural and anthropogenic sources Global dimming and brightening Aerosol opxcal depth (AOD) Sun photometer Satellite monitoring

18 NOAA s Annual Greenhouse Gas Index The NOAA Annual Greenhouse Gas Index (AGGI) measures the commitment society has already made to living in a changing climate. It is based on the highest quality atmospheric observaxons from sites around the world. Its uncertainty is very low. (MLO website) (AGGI) The AGGI in 2016 was 1.40, which means that we ve turned up the warming influence by 40% since It took ~240 years for the AGGI to go from 0 to 1, i.e., to reach 100%, and 26 years for it to increase by another 40%. In terms of CO2 equivalents, the atmosphere in 2016 contained 489 ppm, of which 403 is CO2 alone. The rest comes from other gases. CO2 is by far the largest contributor to the AGGI in terms of both amount and rate of increase. Note: The IPCC suggests that a constant concentraxon of CO2 alone at 550 ppm would lead to an average increase in Earth s temperature of ~3 C (5.4 F). Source: MLO website

19 NOAA s Annual Greenhouse Gas Index (AGGI)

20 Aerosol Effects of Solar RadiaXon

21 Changing Atmosphere AR5 WG1 Drae report (2013, Chapter 2)

22 Changing Atmosphere AR5 WG1 Drae report (2013, Chapter 2)

23 Changing Climate Annual anomalies calculated with respect to the 20 th century mean. hlps://

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26 Can We Trust the Data? Weather observaxons are the basis for assessing climate variability and change Instrument and human error occur and can lead to spurious trends Stringent quality assessment and quality control (QA/QC) are essenxal See how NOAA assures good data quality: hlps:// processing-climate-data

27 Types of data problems Missing data Sensor change CalibraXon change CalibraXon drie Flatliner Spikes DetecXon: Range tesxng Outlier detecxon Spike detecxon Homogeneity tesxng: double mass curves Change-point detecxon

28 Changing Climate LSAT Land Surface Air Temperature AR5 WG1 Drae report (2013, Chapter 2)

29 Changing Climate SST Sea Surface Temperature NMAT Night Marine Air Temperature AR5 WG1 Drae report (2013, Chapter 2)

30 Changing Climate SST Sea Surface Temperature From Satellites and in situ records AR5 WG1 Drae report (2013, Chapter 2)

31 Changing Climate A hiatus? AR5 WG1 Drae report (2013, Chapter 2)

32 Global Warming Hiatus? Global mean surface temperature (GMST) warming was slower during the period compared with the warming of the last half of the 20 th century 1 RadiaXve imbalance at the top of the atmosphere (TOA) of about W m -2 during the past two decades based on observaxons 2 During the past 50 years, the oceans absorbed ~90% of added energy 2 The other 10% went to melxng ice and warming land surface and atmosphere 2 1 Yan, X.-H., Boyer, T., Trenberth, K., Karl, T. R., Xie, S.-P., Nieves, V., Tung, K.-K. and Roemmich, D. (2016), The global warming hiatus: Slowdown or redistribuxon?. Earth's Future, 4: doi: /2016ef Balmaseda, M. A., K. E. Trenberth, and E. Källén (2013), DisXncXve climate signals in reanalysis of global ocean heat content, Geophys. Res. Le0., 40, , doi: /grl

33 Global Warming Hiatus? GMST is strongly related to global sea surface temperature (SST). SST Sea Surface Temperature NMAT Night Marine Air Temperature LSAT Land Surface Air Temperature AR5 WG1 Drae report (2013, Chapter 2) AR5 WG1 Drae report (2013, Chapter 2)

34 Global Warming Hiatus? Sea surface temperature (SST) increases stalled in the 2000s, when warming should have been increasing due to increasing GHG concentraxons 1 In parxcular, the energy imbalance during was hard to explain, leading to the concept of missing energy. 1 1 Balmaseda, M. A., K. E. Trenberth, and E. Källén (2013), DisXncXve climate signals in reanalysis of global ocean heat content, Geophys. Res. Le0., 40, , doi: /grl SST Sea Surface Temperature NMAT Night Marine Air Temperature AR5 WG1 Drae report (2013, Chapter 2)

35 Dis:nc:ve climate signals in reanalysis of global ocean heat content Figure 1. OHC integrated from 0 to 300 m (grey), 700 m (blue), and total depth (violet) from ORAS4, as represented by its 5 ensemble members. The Xme series show monthly anomalies smoothed with a 12 month running mean, with respect to the base period. Hatching extends over the range of the ensemble members and hence the spread gives a measure of the uncertainty as represented by ORAS4 (which does not cover all sources of uncertainty). The verxcal colored bars indicate a 2 year interval following the volcanic erupxons with a 6 month lead (owing to the 12 month running mean), and the El Niño event again with 6 months on either side. On lower right, the linear slope for a set of global heaxng rates (W m 2 ) is given. Geophysical Research LeBers Volume 40, Issue 9, pages , 10 MAY 2013 DOI: /grl hlp://onlinelibrary.wiley.com/doi/ /grl.50382/full#grl50382-fig-0001

36 Global Warming Hiatus? During , the heat content and temperature of the upper ocean (upper 300 m) was stable. 1 But, the deep ocean (below 300 m depth) conxnued warming. 1 1 Balmaseda, M. A., K. E. Trenberth, and E. Källén (2013), DisXncXve climate signals in reanalysis of global ocean heat content, Geophys. Res. Le0., 40, , doi: /grl the GMST phenomenon is a surface characterisxc that does not represent a slowdown in warming of the climate system but rather is an energy redistribuxon within the oceans. 2 2 Yan, X.-H., Boyer, T., Trenberth, K., Karl, T. R., Xie, S.-P., Nieves, V., Tung, K.-K. and Roemmich, D. (2016), The global warming hiatus: Slowdown or redistribuxon?. Earth's Future, 4: doi: /2016ef000417

37 Probable Cause of Slow Warming During MulX-decadal swings in the intensity of the oceanic circulaxon system that moves heat to the deep ocean

38 Global Warming Hiatus? El Niño-aided warming during has now erased any noxon that global warming has paused or reversed. The global warming hiatus: Slowdown or redistribu:on? Yan, X.-H., Boyer, T., Trenberth, K., Karl, T. R., Xie, S.-P., Nieves, V., Tung, K.-K. and Roemmich, D. (2016), The global warming hiatus: Slowdown or redistribuxon?. Earth's Future, 4: doi: /2016ef Earth's Future Volume 4, Issue 11, pages , 22 NOV 2016 DOI: /2016EF hlp://onlinelibrary.wiley.com/doi/ /2016ef000417/full#ee2156-fig-0001

39 Facts

40 AlternaXve Facts hlps://

41 2014, 2015, 2016, and 2017 were the four warmest years on record All of the ten warmest years of the 137-year record occurred aeer 1997 hlps://

42 Changing Climate AR5 WG1 Drae report (2013, Chapter 2)

43 Changing Climate The hiatus Recent analysis by Balmaseda et al. (2013) shows that during the upper ocean warming hiatus the ocean has conxnued to absorb heat During the past decade, 30% of warming has taken place below the 700 m depth VariaXons in surface winds are responsible for changes in the verxcal distribuxon of ocean heat storage Balmaseda et al. (2013, Geophysical Research Le0ers 40: )

44 Changing Climate Balmaseda et al. (2013, Geophysical Research Le0ers 40: )

45 Final Thoughts Basis of climate change theory is not new. Svante Arrhenius, a Swedish physical chemist, published a paper in 1896 in which he calculated the strength of the greenhouse effect due to CO2 and esxmated that doubling its concentraxon would cause global warming of about 5-6 deg C. Svante Arrhenius. His 159 th birthday is on Feb. 19.

46 Final Thoughts With pre-exisxng, well-tested scienxfic theory predicxng that CO 2 emissions would lead to a warming climate, it was not surprising to most scienxsts when observaxons began to show that global temperature was increasing. One of the most common tricks used by climate change deniers to confuse the media and the general public is the cherry pick observaxons and model predicxons. The recent warming hiatus has provided a huge opportunity for deniers to create doubt and thereby slow efforts to reduce emissions. None of the disinformaxon put out be deniers will change the facts.

47 The Facts Burning fossil fuels and cu ng of forests cause emissions of CO 2. CO 2 emissions cause atmospheric CO 2 concentraxon to increase. The amount of upward longwave radiaxon absorbed by the atmosphere is dependent on the CO 2 concentraxon. If CO 2 concentraxon increases, global temperature will increase as a result. CO 2 concentraxon has increased from 280 to 400 ppm since the start of the Industrial RevoluXon. Global temperature has increased by about 0.8 deg C. The facts speak for themselves.

48 Global temperature change animaxon eoimages.gsfc.nasa.gov/images/imagerecords/89000/89469/globaltemp_chart_2016.gif