FAQ - climate change

Frequently asked questions.

 

How many of us are commuting? ...are living on campus?

8 of you are commuting. 9 are living on campus.

Biggest cause?

Two major ones:

  1. Burning fossil fuels: coal, oil (includes gasoline and diesel fuel), natural gas. See $CO_2$ and Greenhouse Emissions (Our World in Data). Some surprises:
    • $CO_2$ emissions continue to rise, but per-capita emissions are dropping in economically advanced countries -- including the major emitters China and the USA.
    • The price of renewable energy and batteries have dropped dramatically, and now new solar and new wind are almost always cheaper than fossil fueld energy.
  2. Deforestation results in the carbon in all those trees, and from soil that has been disturbed returning to the atmosphere as $CO_2$. Agriculture drives much deforestation. See Environmental Impacts of Food Production [Our World in Data]. Some surprises:
    • What kind of food you eat (less beef, more plants) has a much greater impact on carbon emissions than how far the food has travelled to reach you.

Will farmers need to adapt [as the climate warms]?

Yes! Farmers will need to

  • Adapt to a warmer climate,
  • Become more resilient to extreme weather events,
  • Use less water,
  • Increasing productivity (roughly measured by more calories / acre) would allow more land to return to forests

What can we do about climate change??

All kinds of things! As climate scientist Katharine Hayhoes says, there is no silver bullet to deal with climate change, but we have "silver buckshot"!

Project Drawdown researches possible solutions, estimates costs and climate impacts for each one, and publishes the results...

  • Drawdown.org, Table of Solutions: For each solution they estimate the $CO_2$ (equivalent) emissions savings in two ways:
    • Scenario 1 is easier (+2.0 C temperature rise by 2100).
    • Scenario 2 is more aggressive (only +1.5 C temperature rise by 2100).

What is the difference between 'Climate Change' and 'Global Warming'?

These terms, and others, like 'Climate Crisis', all refer to the same thing:

  • Starting with the industrial revolution, in the mid 1700s, Western Europeans figured out how to make machines powered by coal--a fossil fuel, resulting from plants and organic matter buried for millions of years underground--instead of using only animals or people for power.

    Wikimedia, Photograph of a painting (1831) of St. Rollox Chemical Works at the opening of the Garnkirk and Glasgow railway
  • Burning coal, and eventually other fossil fuels, like oil and "natural" gas, produces carbon-dioxide.

    Carbon-dioxide makes up less than 1% of the atmosphere. But unlike nitrogen (78%) and oxygen (21%), $CO_2$ traps heat energy that would otherwise escape back into space. It's like a blanket for the Earth.

    We've known quantitatively since 1896 (Svante Arrhenius (at right), pushed by his friend Arvid Högbom) what Earth's average temperature will be, depending on the amount of $CO_2$ in the atmosphere.

    "We figured out the Greenhouse Effect closer to the industrial revolution than today" (XKCD)

  • Put on enough blankets, and you'll warm up! Since the pre-industrial era, humans have found more and more ways to get useful things done by burning fossil fuels. And the amount of $CO_2$ in our atmosphere has been accelerating. In pre-industrial times, we estimate that there were 280 parts per million--280 molecules of $CO_2$ out of every 1 million molecules).

    Google to find out how many "ppm" of CO2 there are in the atmosphere today?

    To figure the percentage increase: $$\frac{\text{ ppm today } - 280}{280}\times 100=\text{% change}.$$

  • At the 21st COP meeting in Paris, representatives of 196 countries brought together by the UN agreed to...

      "...limit global warming to well below 2, preferably to 1.5 degrees Celsius, compared to pre-industrial levels." (UNFCC.int)

    Right now we're at about 1.2 C (2.2 Fahrenheit) above pre-industrial levels. 2 C = 3.6 F. >