Climate Change Trends and Projections

On this page, you’ll find links to article containing information on trends and projections relating to climate change.

Climate Change: Global Temperature

  • From NOAA

Excerpts:

  • “Given the size and tremendous heat capacity of the global oceans, it takes a massive amount of heat energy to raise Earth’s average yearly surface temperature even a small amount. The 2-degree increase in global average surface temperature that has occurred since the pre-industrial era (1880-1900) might seem small, but it means a significant increase in accumulated heat.”
  • “Despite La Niña, 2020 ranked as the second-warmest year in the 141-year record for the combined land and ocean surface, and land areas were hottest on record. Many parts of Europe and Asia were record warm, including most of France and northern Portugal and Spain, most of the Scandinavian Peninsula, Russia, and southeastern China. An even larger portion of the globe was much warmer than average, including most of the Atlantic and Indian Oceans. The heat reached all the way to the Antarctic, where the station at Esperanza Base, at the tip of the Antarctic Peninsula, appeared to set a new all-time record high temperature of 65.1 degrees Fahrenheit (18.4 degrees Celsius) on February 6, 2020.”
  • “The 10 warmest years on record have all occurred since 2005, and 7 of the 10 have occurred just since 2014.”

Climate Forecast for 202s Is Warmer, Stormier, and More Extreme

Excerpts:

  • “…in the last decade, the ability to model the climate has advanced so much that people can determine whether human-generated global warming made a storm wetter or a drought longer than it otherwise would have been.”
  • “The Arctic is warming faster than lower latitudes, and this is affecting the wind patterns –especially the jet stream. Researchers say that a weakening of those winds is part of the reason storms such as Hurricane Harvey stall, and dry air lingers in other places for weeks.”
  • “Because we’ve increased the earth’s atmospheric carbon by more than 40%, the oceans are warmer, and the air above the ocean is warmer and wetter, and the sea level is already a little higher. That contributes to making storms more intense, with heavier, prolonged rainfall, as people witnessed with Harvey in Houston and Florence in the Carolinas. The planet’s dry climates are getting drier, and the wet, wetter.”
  • “Adding fuel to the situation (the misinformation campaign led against climate science) was a loss of trust in all of science following the so-called replication crisis, in which social science was exposed as contaminated with flimsy and erroneous results. Much of established nutrition research was overturned, and many medical findings were deemed impossible to reproduce. But this had nothing to do with basic, well-established physics and Earth science. The periodic table didn’t get torn up, electricity still works as predicted, and Einstein’s pedestal has only been elevated.”

Were the predictions we made about climate change 20 years ago accurate? Here’s a look

Excerpts:

  • “Overall, we’re running quite close to the projections made in 2000 for carbon dioxide concentration, global temperature and sea level…”
  • “Since the early 1990s, the carbon dioxide level in the Earth’s atmosphere has jumped from about 358 parts per million to nearly 412 ppm, according to the National Oceanic and Atmospheric Administration. That’s a 15% rise in 27 years.”
  • “Since 1992, the global sea level has risen on average 2.9 millimeters a year. That’s a total of 78.3 millimeters, according to NOAA.”
  • “Both of the world’s giant ice sheets have lost tremendous amounts of ice in the past two to three decades: The Greenland ice sheet lost 5.2 trillion tons of ice from 1993 to 2018, according to a study in the Proceedings of the National Academy of Sciences.”
  • “The Antarctic ice sheet lost 3 trillion tons of ice from 1992 to 2017, according to a study in the journal Nature.”
  • “Since 1993, there have been 212 weather disasters that cost the United States at least $1 billion each, when adjusted for inflation.”
  • “In total, they cost $1.45 trillion and killed more than 10,000 people. That’s an average of 7.8 such disasters per year since 1993, compared with 3.2 per year from 1980 to 1992, according to NOAA.”
  • “By and large, our models have gotten it right, plus or minus a little bit,” said Zeke Hausfather, a University of California-Berkeley scientist.”
  • “The global average temperature rose a tad more than a degree Fahrenheit since the mid-’90s, according to NOAA.”
  • “The global temperature projections were just about on the money…”
  • “These climate models weren’t designed to predict decade-by-decade variability, Henson said, so we didn’t fully anticipate the slowdown in global atmospheric warming in the first decade of this century and the much more rapid increase in the 2010s, both of which were linked to the evolving rate of heat storage in the ocean.”
  • “The annual average extent of Arctic sea ice has shrunk from 4.7 million square miles in 1992 to 3.9 million square miles in 2019, according to the National Snow and Ice Data Center. That’s a 17% decrease.”
  • “The number of acres burned by wildfires in the USA has more than doubled from a five-year average of 3.3 million acres in the 1990s to 7.6 million acres in 2018, the National Interagency Fire Center said.”
  • “We’re also appreciating the threat posed by ‘sunny day’ flooding much more than we did in 2000,” Henson said. “Tidal flooding is far more frequent on many parts of the Gulf and Atlantic coast than it was 20 years ago, and NOAA has projected that some locations could see more than 80 flood days a year as soon as the 2040s.”

Predictions of Future Global Climate (From the Center for Science Education)  

Excerpts: 

  • “During the 21st Century, various computer models predict that Earth’s average temperature will rise between 1.8° and 4.0° Celsius (3.2° and 7.2° F).”
  • “Warmer average global temperature will cause a higher rate of evaporation, causing the water cycle to “speed up”. More water vapor in the atmosphere will lead to more precipitation. According to models, global average precipitation will most likely increase by about 3-5% witha minimum increase of at least 1% and a maximum increase of about 8%. Yet, changes in precipitation will not be evenly distributed. Some locations will get more snow, others will see less rain. Some places will have wetter winters and drier summers.”
  • “During the 20th Century, sea level rose about 10 to 20 cm (4 to 8 inches). Thermal expansion and melting ice each contributed about half of the rise, though there is some uncertainty in the exact magnitude of the contribution from each source. By the year 2100, models predict sea level will rise between about 20 and 50 cm (8 to 20 inches) above late 20th Century levels. Thermal expansion of sea water is predicted to account for about 75% of future sea level rise according to most models.”
  • “Large-scale ocean currents called thermohaline circulation, driven by differences in salinity and temperature, may also be disrupted as climate warms. Changes in precipitation patterns and the influx of fresh water into the oceans from melting ice can alter salinity. Changing salinity, along with rising water temperature, may disrupt the currents. In an extreme case, thermohaline circulation could be disrupted or even shut down in some parts of the ocean, which could have large effects on climate.”
  • “Even if greenhouse gas emissions were halted immediately, we are committed to a certain amount of global warming (an estimated 0.5° C) because of the amounts of these gases already present in the atmosphere. This is called “climate commitment”.”

Think 2020’s disasters are wild? Experts predict worse in the future

Notes:

  • This article was published in September of 2020

Excerpts:

  • “Freak natural disasters — most with what scientists say likely have some kind of climate change connection — seem to be everywhere in the crazy year 2020. But experts say we’ll probably look back and say those were the good old days, when disasters weren’t so wild.”
  • “…what’s happening now is just the type of crazy climate scientists anticipated 10 or 20 years ago.”
  • “California is in the midst of a nearly 20-year mega-drought, the first of its kind in the United States since Europeans arrived…”

Climate Change: Global Sea

Notes:

  • Published by NOAA in January 2021

Excerpts:

  • “Global mean sea level has risen about 8–9 inches (21–24 centimeters) since 1880, with about a third of that coming in just the last two and a half decades. The rising water level is mostly due to a combination of meltwater from glaciers and ice sheets and thermal expansion of seawater as it warms. In 2019, global mean sea level was 3.4 inches (87.6 millimeters) above the 1993 average—the highest annual average in the satellite record (1993-present). From 2018 to 2019, global sea level rose 0.24 inches (6.1 millimeters).”
  • By the end of the century, global mean sea level is likely to rise at least one foot (0.3 meters) above 2000 levels, even if greenhouse gas emissions follow a relatively low pathway in coming decades.