Fossil fuel combustion is the main source of CO2. Per unit of energy, coal emits most, followed by oil and gas. #climateeconomics
Land use change and cement production are other sources of CO2. Specialized industries emit halocarbons. #climateeconomics
Methane results from paddy rice, livestock, waste, and gas leakage, nitrous oxide from agricultural soils. #climateeconomics
CO2 emissions equal population times income per capita times energy use per output times emissions per unit of energy. #climateeconomics
World CO2 emission +2.0%/year 1971-2013: population +1.5%, income +1.8%, energy per GDP -1.4%, CO2 per energy +0.1%. #climateeconomics
Scenarios are not implausible, internally consistent descriptions of alternative futures #climateeconomics
Existing scenarios of future greenhouse gas emissions do not reflect the full range of historical experience. #climateeconomics
There's not enough conventional oil and gas to substantially change climate. Future climate is driven by their replacements. #climateeconomics
Reduced population and economic growth would reduce emissions, but few elected governments would opt for this. #climateeconomics
Technological change reduces emissions but current effort would need to be trebled to stabilize emissions. #climateeconomics
Behavioural change reduces emissions too, but habits are hard to change and market imperfections waste a lot of energy. #climateeconomics
Carbon-free fuels are another option but nuclear and hydropower are unpopular. #climateeconomics
Renewables are (very) expensive; volatile and unpredictable; and bring their own environmental problems. #climateeconomics
CO2 can be captured and stored at a price. Scale, permanence, and safety are issues. CCS is an end-of-pipe solution. #climateeconomics
Slowing deforestation would reduce emissions but if that were easy it would have been done long ago. #climateeconomics
Geoengineering is a risky option. There are concerns about who would decide to geoengineer the global climate. #climateeconomics
Chapter 2 of #climateeconomics amazon.co.uk/Climate-Econom…
Slides, videos, data, quizzes, further reading on #climateeconomics sites.google.com/site/climateco…
