2021 was tied for the sixth warmest year on NASA’s record, stretching more than a century. Because the record is global, not every place on Earth experienced the sixth warmest year on record. Some places had record-high temperatures, and we saw record droughts, floods and fires around the globe. Credits: NASA’s Scientific Visualization Studio/Kathryn Mersmann
Lee esta nota de prensa en español aquí.
Earth’s global average surface temperature in 2021 tied with 2018 as the
sixth warmest on record, according to independent analyses done by NASA and the
National Oceanic and Atmospheric Administration (NOAA).
Continuing the planet’s long-term warming trend, global temperatures in
2021 were 1.5 degrees Fahrenheit (0.85 degrees Celsius) above the average for
NASA’s baseline period, according to scientists at NASA’s Goddard Institute for
Space Studies (GISS) in New York. NASA uses the period from 1951-1980 as a
baseline to see how global temperature changes over time.
Collectively, the past eight years are the warmest years since modern
recordkeeping began in 1880. This annual temperature data makes up the global temperature
record – which tells scientists the planet is warming.
According to NASA’s temperature record, Earth in 2021 was about 1.9 degrees
Fahrenheit (or about 1.1 degrees Celsius) warmer than the late 19th century
average, the start of the industrial revolution.
“Science leaves no room for doubt: Climate change is the existential threat
of our time,” said NASA Administrator Bill Nelson. “Eight of the top 10 warmest
years on our planet occurred in the last decade, an indisputable fact that
underscores the need for bold action to safeguard the future of our country –
and all of humanity. NASA’s scientific research about how Earth is
changing and getting warmer will guide communities throughout the world,
helping humanity confront climate and mitigate its devastating effects.”
This warming trend around the globe is due to human activities that have
increased emissions of carbon dioxide and other greenhouse gases into the
atmosphere. The planet is already seeing the effects of global warming: Arctic sea ice is declining, sea levels are rising, wildfires are
becoming more severe and animal migration
patterns are shifting. Understanding how the planet is changing
– and how rapidly that change occurs – is crucial for humanity to prepare for
and adapt to a warmer world.
Weather stations, ships, and ocean buoys around the globe record the
temperature at Earth’s surface throughout the year. These ground-based
measurements of surface temperature are validated with satellite data from the
Atmospheric Infrared Sounder (AIRS) on NASA’s Aqua satellite. Scientists
analyze these measurements using computer algorithms to deal with uncertainties
in the data and quality control to calculate the global average surface
temperature difference for every year. NASA compares that global mean temperature
to its baseline period of 1951-1980. That baseline includes climate patterns
and unusually hot or cold years due to other factors, ensuring that it
encompasses natural variations in Earth’s temperature.
Many factors affect the average temperature any given year, such as La Nina
and El Nino climate patterns in the tropical Pacific. For example, 2021 was a
La Nina year and NASA scientists estimate that it may have cooled global
temperatures by about 0.06 degrees Fahrenheit (0.03 degrees Celsius) from what
the average would have been.
A separate, independent analysis by NOAA also concluded that the global
surface temperature for 2021 was the sixth highest since record keeping began
in 1880. NOAA scientists use much of the same raw temperature data in their analysis
and have a different baseline period (1901-2000) and methodology.
“The complexity of the various analyses doesn’t matter because the signals
are so strong,” said Gavin Schmidt, director of GISS, NASA’s leading center for
climate modeling and climate change research. “The trends are all the same
because the trends are so large.”
NASA’s full dataset of
global surface temperatures for 2021, as well as details of how
NASA scientists conducted the analysis, are publicly available from GISS.
GISS is a NASA laboratory managed by the Earth Sciences Division of the agency’s Goddard Space Flight Center in Greenbelt, Maryland. The laboratory is affiliated with Columbia University’s Earth Institute and School of Engineering and Applied Science in New York.
For more information about NASA’s Earth science missions, visit: https://www.nasa.gov/earth
No comments:
Post a Comment