Closer Than You Think

Related image

The reality of NASA’s research to some will be like mud on the bottom of their boots. Okay, but exactly how deep is that mud?

 

The evidence for rapid climate change is compelling:


Global Temperature Rise

  • The planet's average surface temperature has risen about 2.0 degrees Fahrenheit (1.1 degrees Celsius) since the late 19th century
    The planet’s average surface temperature has risen about 1.62 degrees Fahrenheit (0.9 degrees Celsius) since the late 19th century, a change driven largely by increased carbon dioxide and other human-made emissions into the atmosphere.4 Most of the warming occurred in the past 35 years, with the five warmest years on record taking place since 2010. Not only was 2016 the warmest year on record, but eight of the 12 months that make up the year — from January through September, with the exception of June — were the warmest on record for those respective months. 5

Warming Oceans

  • The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of more than 0.4 degrees Fahrenheit since 1969.
    The oceans have absorbed much of this increased heat, with the top 700 meters (about 2,300 feet) of ocean showing warming of more than 0.4 degrees Fahrenheit since 1969.6

Shrinking Ice Sheets

  • The Greenland and Antarctic ice sheets have decreased in mass
    The Greenland and Antarctic ice sheets have decreased in mass. Data from NASA’s Gravity Recovery and Climate Experiment show Greenland lost an average of 286 billion tons of ice per year between 1993 and 2016, while Antarctica lost about 127 billion tons of ice per year during the same time period. The rate of Antarctica ice mass loss has tripled in the last decade.7Image: Flowing meltwater from the Greenland ice sheet

    Glacial Retreat

    • Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.
      Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.8Image: The disappearing snowcap of Mount Kilimanjaro, from space.


    Decreased Snow Cover

    • Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier
      Satellite observations reveal that the amount of spring snow cover in the Northern Hemisphere has decreased over the past five decades and that the snow is melting earlier.9

    Sea Level Rise

    • Global sea level rose about 8 inches in the last century. The rate in the last two decades, however, is nearly double that of the last century and is accelerating slightly every year
      Global sea level rose about 8 inches in the last century. The rate in the last two decades, however, is nearly double that of the last century and is accelerating slightly every year.10Image: Republic of Maldives: Vulnerable to sea level rise


    Declining Arctic Sea Ice

    • Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades
      Both the extent and thickness of Arctic sea ice has declined rapidly over the last several decades.11Image: Visualization of the 2012 Arctic sea ice minimum, the lowest on record

    Extreme Events

    • Glaciers are retreating almost everywhere around the world — including in the Alps, Himalayas, Andes, Rockies, Alaska and Africa.
      The number of record high temperature events in the United States has been increasing, while the number of record low temperature events has been decreasing, since 1950. The U.S. has also witnessed increasing numbers of intense rainfall events.12

    Ocean Acidification

    • Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent
      Since the beginning of the Industrial Revolution, the acidity of surface ocean waters has increased by about 30 percent.13,14 This increase is the result of humans emitting more carbon dioxide into the atmosphere and hence more being absorbed into the oceans. The amount of carbon dioxide absorbed by the upper layer of the oceans is increasing by about 2 billion tons per year.15,16

    References

    1. IPCC Fifth Assessment Report, Summary for Policymakers

      B.D. Santer et.al., “A search for human influences on the thermal structure of the atmosphere,” Nature vol 382, 4 July 1996, 39-46

      Gabriele C. Hegerl, “Detecting Greenhouse-Gas-Induced Climate Change with an Optimal Fingerprint Method,” Journal of Climate, v. 9, October 1996, 2281-2306

      V. Ramaswamy et.al., “Anthropogenic and Natural Influences in the Evolution of Lower Stratospheric Cooling,” Science 311 (24 February 2006), 1138-1141

      B.D. Santer et.al., “Contributions of Anthropogenic and Natural Forcing to Recent Tropopause Height Changes,” Science vol. 301 (25 July 2003), 479-483.

    2. In the 1860s, physicist John Tyndall recognized the Earth’s natural greenhouse effect and suggested that slight changes in the atmospheric composition could bring about climatic variations. In 1896, a seminal paper by Swedish scientist Svante Arrhenius first predicted that changes in the levels of carbon dioxide in the atmosphere could substantially alter the surface temperature through the greenhouse effect.

    3. National Research Council (NRC), 2006. Surface Temperature Reconstructions For the Last 2,000 Years. National Academy Press, Washington, D.C.

      http://earthobservatory.nasa.gov/Features/GlobalWarming/page3.php

    4. Levitus, S.; Antonov, J.; Boyer, T.; Baranova, O.; Garcia, H.; Locarnini, R.; Mishonov, A.; Reagan, J.; Seidov, D.; Yarosh, E.; Zweng, M. (2017). NCEI ocean heat content, temperature anomalies, salinity anomalies, thermosteric sea level anomalies, halosteric sea level anomalies, and total steric sea level anomalies from 1955 to present calculated from in situ oceanographic subsurface profile data (NCEI Accession 0164586). Version 4.4. NOAA National Centers for Environmental Information. Dataset. doi:10.7289/V53F4MVP

    5. National Snow and Ice Data Center

      Robinson, D. A., D. K. Hall, and T. L. Mote. 2014. MEaSUREs Northern Hemisphere Terrestrial Snow Cover Extent Daily 25km EASE-Grid 2.0, Version 1. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/MEASURES/CRYOSPHERE/nsidc-0530.001. [Accessed 9/21/18].

      http://nsidc.org/cryosphere/sotc/snow_extent.html

      Rutgers University Global Snow Lab, Data History Accessed September 21, 2018.

    6. R. S. Nerem, B. D. Beckley, J. T. Fasullo, B. D. Hamlington, D. Masters and G. T. Mitchum. Climate-change–driven accelerated sea-level rise detected in the altimeter era. PNAS, 2018 DOI: 10.1073/pnas.1717312115
    7. USGCRP, 2017: Climate Science Special Report: Fourth National Climate Assessment, Volume I [Wuebbles, D.J., D.W. Fahey, K.A. Hibbard, D.J. Dokken, B.C. Stewart, and T.K. Maycock (eds.)]. U.S. Global Change Research Program, Washington, DC, USA, 470 pp, doi: 10.7930/J0J964J6

    8. C. L. Sabine et.al., “The Oceanic Sink for Anthropogenic CO2,” Science vol. 305 (16 July 2004), 367-371

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s