📝 The Thinking Person's Guide to Climate Change
Author: Robert Henson
Part 1 - The Basics - Global Warming in a nutshell
Chapter 1 - Climate Change: A Primer
- Check out the IPCC organization and it's reports.
- Detection and attribution i.e. is the climate Changing, and is it changing because of humans.
- Eg temperature warming at poles is not expected from natural causes.
The spectrum extends anywhere from 0.4° to 2.6°C (0.7°–4.7°F) by 2046–2065 and from 0.3° to 4.8°C (0.5°–8.6°F) by 2081–2100. Importantly, this would be on top of the warming of about 0.6°C (1.1°F) that occurred from the 1850–1900 period to the 1986–2005 comparison period.
There’s nothing magic about the 2°C value, as we’ll see in chapter 14, but it serves as a “do not exceed” guidepost in the Paris Agreement on tackling climate change.
Together, the United States and China account for an ever-increasing slice of the globe’s greenhouse emissions—more than 40%, as of 2014.
Kyoto agreement was binding, but the US and China were not a part of it.
The Paris agreement is self enforced, so is a step back.
Chapter 2 - The Greenhouse Effect
Good analogies: think of temperatures on the moon, which doesn't have an atmosphere. Similarly, a car left in the sun gets really hot. Similarly, the atmosphere traps heat. CO2 is 96 percent of Venus's atmosphere. 0.04 percent off ours. Also it's 25 percent closer to the sun than us. Surface air temperature of 460 degrees celsius. Mercury, although much closer to the sun, has a much lower average temperature due to its thin atmosphere.
Unlike a glass box, the atmosphere doesn't trap heat. It mainly absorbs infrared radiation rising from the earth:
- 30 percent reflected by land (more by snow than forests)
- 20 absorbed by clouds and partially reflected back downwards. Clouds, water vapour, greenhouse gases.
- 50 absorbed by land, forests oceans etc
- Note that visible light seems to be scattered out, it's only the (long wave) infrared radiation that bounces inside the atmosphere.
Positive feedback loop makes it worse: more CO2, more warmth, more water evaporating from oceans, and that doubles the impact.
Water vapour: less greenhouse effect compared to CO2 and methane, but large quantity. If temperatures increase, the air can hold more vapour, which again traps more heat.
Since 1958, measurements have been taken in Hawaii's Mauna Loa. Being remote and high, it is far enough away from industrial effects that it serves as a global measurement of CO2 increase.
Todo explain why the stratosphere has been cooling while the surface has been warming.
Chapter 3 - Who’s Responsible?
Emissions breakdown:
- Transport 14
- Buildings 18
- Industry 29
- Other energy 14
- Agriculture, forestry and other land use 20
- Landfills and waste water 3
Part 2 - The Symptoms: WHAT’S HAPPENING NOW, AND WHAT MIGHT HAPPEN IN THE FUTURE
CHAPTER 4 - Extreme Heat
Heat affects mortality because high temperatures generate more ozone.
It irritates the lungs and makes people more vulnerable to other pollutants.
PM2.5 and PM10 particles also accumulate during a heat wave. Heavy metals, sulphates, nitrates etc bypass the respiratory filters, causing lung problems and increasing the risk of heart attacks.
Measuring deaths from heat waves: not easy since it's indirect. It mainly claims lives of the very young or very old. But if tje argument was that the very old simply doed a bit before their time, we should see that the mortality numbers dipped by a similar percentage after the heat wave. But what we observe are that there are 3xcess deaths above what we'd expect if some deaths were simply happening earlier. I.e. there are people who are dying before 'their time'.
How to measure: things like absolute values don't give a good sense when comparing different cities across the world. Monthly max / min doesn't capture a week long heat wave. And so on. So a good measure is 'Percentile departure' i.e. the number of days that land among the hottest of all days in that month's long term record, based on percentage (i.e. Hottest 10 %, hottest 5%, 1% etc.)