Science is about using observation and reason to understand the physical world. Here are some of the latest observations showing how increasing greenhouse gases are changing the Earth.

CO2: Man is now putting about 30 billion tons of carbon dioxide into the air each year. About half of it dissolves in the ocean, making them 20% more acidic, and the rest increases the concentration in the air.

 The line is wavy because CO2 concentration in the Northern Hemisphere decreases in spring as plants begin to grow.

Temperature: CO2 is one of the greenhouse gases that warms the Earth, and NASA’s graph shows how its increase is changing the Earth’s temperature:

.    The Sun: The current global warming is often wrongly attributed to an increase in the intensity of the sun. The sunspot activity does not show up above the noise in the temperature record above – and the solar irradiance (yellow line) increased slightly until 1960 and has declined slightly since then.

Arctic Ice: The Arctic is warming faster than the rest of the Earth. Where once the Arctic Ocean was solid ice, ships can now sail through in the summer.

Many of the changes in the Earth are subtle, but this NASA picture clearly shows  how the Arctic Ocean is changing:

The warming Arctic is affecting ocean currents and the jet stream, sometimes causing extreme weather patterns in the Northern Hemisphere.

Ice: As the Earth warms, glaciers and ice are disappearing.

Antarctica: Research by Steig and by O’Donnell  show that Antarctica is warming. The warmer oceans result in more snowfall which increases the inland glacier mass, but the erosion of ice by the warmer oceans is causing an overall loss of ice mass.

Greenland: The Greenland ice sheets are also beginning to decline. Melting Greenland’s ice would cause sea levels to rise 10 feet,

Ocean Level Rise: The melting ice sheets, melting glaciers, and thermal expansion are causing the oceans to rise by about 3 mm per year which, though it seems small, amounts to an increase in ocean volume of 1190 cubic kilometers/yr.

Severe Weather: Warmer temperatures increase both the rate of evaporation and the energy and moisture in the air. This has doubled the incidence of severe weather, floods, droughts, and wildfires.  Large secondary insurance companies, such as Suisse Re and Munich Re, now consider global warming a risk factor as there has been a fivefold increase in billion-dollar weather events in the last 30 years.

Food Production: The increasing temperatures and droughts are expected to decrease food production worldwide.

Extreme Temperatures: Climate scientists now have enough data and computing power to estimate the probability of extreme weather events. The figure below, from a paper by Hansen et al., shows how the temperature distribution has varied over the past 60 years. Extremely hot temperatures, those over 3 standard deviations from the mean, are now over 20 times as probable as in the 1950 – 1980 period. Extreme temperatures that affected 1% of the landmass in 1980 now affect almost 10% annually.

Other greenhouse gases: With increased fracking to produce natural gas, and the increasing use of nitrogen fertilizers on crops, the concentration of other greenhouse gases is increasing. Methane now accounts for about one-fourth of the global warming we are experiencing.

Note: This was posted on 08/31/2011 and updated on 04/03/2012,08/11/2012, and 02/12/2013. It was reposted on 08/27/2021.

(c) 2026  J.C. Moore

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