Tony Heller on Greenland's Mass Balance

Greenland's Contribution to Sea Level Rise Since 1992

In 2019, Tony Heller posted on his blog that "Over the past three years, Greenland’s surface has gained 1.2 trillion tons of new ice... Experts in the press corps have generously interpreted the data for us, and determined that there is a climate emergency and it is President Trump’s fault." He then showed graphs supporting that Greenland's surface mass balance (SMB) did indeed gain ice each of those years, totaling 1.2 trillion tons of ice. 

What Heller doesn't tell you is that Greenland's SMB gains ice pretty much every year, but it also loses ice every year due to glacial calving and basal melting; this is referred to as discharge (D). In order to assess whether Greenland gained or lost ice, what is referred to as total mass balance (TMB) you have to account for both SMB and D. The equation for this is not that hard:

TMB = SMB + D

Heller was capable of looking up the value for SMB but neglected to look up values for D. So I pointed this out to him in the comments. His response was rather entertaining.


Apparently, data Heller can use to say Greenland's surface gained ice is fine, but the data that shows that Greenland as a whole has lost ice every year since the 1990s is "difficult to measure and is largely unrelated to climate." It's not like Heller doesn't have access to the data that proves him wrong, and I linked to an IMBIE study that would give him the data he needed to produce an accurate accounting of the Greenland Ice Sheet.[8]


The study provides a comprehensive accounting of the GrIS ass balance from 1992 to 2018. They conclude, "Cumulative ice losses from Greenland as a whole have been close to the rates predicted by the Intergovernmental Panel on Climate Change for their high-end climate warming scenario17, which forecast an additional 70 to 130 millimetres of global sea-level rise by 2100 compared with their central estimate." This what the cumulative mass loss looks like.


Below I compiled a list of references that provide evidence that is more than sufficient to conclude that Greenland is in fact losing ice and contributing to sea level rise.


[1] Norris, J., Allen, R., Evan, A. et al. Evidence for climate change in the satellite cloud record. Nature 536, 72–75 (2016). https://doi.org/10.1038/nature18273
https://www.nature.com/articles/nature18273?foxtrotcallback=true

[2] Hofer 2017, "Decreasing cloud cover drives the recent mass loss on the Greenland Ice Sheet." Science Advances 28 Jun 2017: Vol. 3, no. 6, e1700584 DOI: 10.1126/sciadv.1700584
https://advances.sciencemag.org/content/advances/3/6/e1700584.full.pdf

[3] Box et al, “Global sea-level contribution from Arctic land ice: 1971–2017” Environmental Research Letters 13.12 (2018)
https://iopscience.iop.org/article/10.1088/1748-9326/aaf2ed

[4] Michael Bevis, Christopher Harig, Shfaqat A. Khan, Abel Brown, Frederik J. Simons, Michael Willis, Xavier Fettweis, Michiel R. van den Broeke, Finn Bo Madsen, Eric Kendrick, Dana J. Caccamise, Tonie van Dam, Per Knudsen, Thomas Nylen. Accelerating changes in ice mass within Greenland, and the ice sheet’s sensitivity to atmospheric forcing. Proceedings of the National Academy of Sciences Feb 2019, 116 (6) 1934-1939; DOI: 10.1073/pnas.1806562116
https://www.researchgate.net/publication/330549231_Accelerating_changes_in_ice_mass_within_Greenland_and_the_ice_sheet's_sensitivity_to_atmospheric_forcing

[5] JĂ©rĂ©mie Mouginot, Eric Rignot, Anders A. Bjørk, Michiel van den Broeke, Romain Millan, Mathieu Morlighem, Brice NoĂ«l, Bernd Scheuchl, Michael Wood, “Forty-six years of Greenland Ice Sheet mass balance from 1972 to 2018” PNAS May 7, 2019 116 (19) 9239-9244; first published April 22, 2019 https://doi.org/10.1073/pnas.1904242116
https://www.pnas.org/content/116/19/9239

[6] Mouginot et al, “Supplementary Information for Forty-six years of Greenland Ice Sheet mass balance from 1972 to 2018” https://www.pnas.org/content/pnas/suppl/2019/04/17/1904242116.DCSupplemental/pnas.1904242116.sapp.pdf

[7] “Dataset_S02 (XLSX).” Supporting Information for Mouginot et al 2019 with D, SMB and TMB data for 1972-2018. Clicking the link should download an Excel file. https://www.pnas.org/highwire/filestream/860129/field_highwire_adjunct_files/2/pnas.1904242116.sd02.xlsx

[8] The IMBIE Team., Shepherd, A., Ivins, E. et al. Mass balance of the Greenland Ice Sheet from 1992 to 2018. Nature 579, 233–239 (2020). https://doi.org/10.1038/s41586-019-1855-2
https://www.nature.com/articles/s41586-019-1855-2

[9] Simonsen, S. B., Barletta, V. R., Colgan, W. T., & Sørensen, L. S. (2021). Greenland Ice Sheet mass balance (1992–2020) from calibrated radar altimetry. Geophysical Research Letters, 48, e2020GL091216. https://doi.org/10.1029/2020GL091216

[10] Slater, T., Lawrence, I. R., Otosaka, I. N., Shepherd, A., Gourmelen, N., Jakob, L., Tepes, P., Gilbert, L., and Nienow, P.: Review article: Earth's ice imbalance, The Cryosphere, 15, 233–246, https://doi.org/10.5194/tc-15-233-2021, 2021.
https://tc.copernicus.org/articles/15/233/2021/?fbclid=IwAR0qOWWg3JLWHHiwtqlOMBKvaNBAKnYbbQBp4vybS_KO8XVNYGaGb96yXKw


Comments

Post a Comment

Popular posts from this blog

Roy Spencer on Models and Observations

Image
A few days ago, Dr. Roy Spencer wrote a piece for the Heritage Foundation called, " Global Warming: Observations vs. Climate Models " ( PDF ) essentially arguing that models show too much warming compared to observations, and if we stick to observations, "global warming offers no justification for carbon-based regulation." He claims to frame his argument in terms of answering three questions: Is recent warming of the climate system materially attributable to anthropogenic greenhouse gas emissions, as is usually claimed? Is the rate of observed warming close to what computer climate models—used to guide public policy—show? Has the observed rate of warming been sufficient to justify alarm and extensive regulation of CO2 emissions? We should keep in mind that this is a political document intended to support the political aims of the Heritage Foundation, and Spencer has carefully selected what he says and doesn't say to fit the political agenda of the Heritage Found
Read more

The Marketing of Alt-Data at Temperature.Global

Image
Temperature.Global (12-month running average, sort of) A few years ago, I started seeing people post links to a new dataset for global temperatures at a website called temperature.global. There are at least four unique features of this dataset. First, the website claims to update global temperature in near real time. Second, every year in the dataset averages below "normal." Third, there is absolutely no transparency regarding their methodology (those who administer it are anonymous, most of the data is hidden, and much of their methodology is unclear). And fourth, what is disclosed about their methodology reveals that what they are calculating is not the Earth's surface temperature. Description of Temperature.Global If you go to the temperature.global website, it becomes almost immediately apparent that this website has little concern for transparency. The website is hosted by Parler (the alternative social network), which if nothing else is pretty odd. There are no name
Read more

Patrick Frank Publishes on Errors Again

Image
Recently I came across yet another paper by Patrick Frank[1] attempting to claim that climate scientists have been underestimating uncertainties in climate-related data. In this paper, he takes aim at GMST data, and he argues that  LiG resolution limits, non-linearity, and sensor field calibrations yield GSATA mean ±2σ RMS uncertainties of, 1900–1945, ±1.7 °C; 1946–1980, ±2.1 °C; 1981–2004, ±2.0 °C; and 2005–2010, ±1.6 °C. Finally, the 20th century (1900–1999) GSATA, 0.74 ± 1.94 °C, does not convey any information about rate or magnitude of temperature change. The resulting GMST graph from his calculations is below. Essentially, he's saying that errors associated with liquid in glass thermometers are so large that we can have no confidence in the global warming trend in the major GMST datasets. Of course, the organizations producing these GMST datasets all evaluate the uncertainties associated with their anomaly values, and their estimates are invariably much smaller - about ±0.05°
Read more