During the Great Depression in the 30s, CO2 emissions fell about 30 percent. However, the 2008 financial crisis only marginal affected CO2 emissions, followed by a sharp rise. Trade policies have been linked to the Great Depression. Could Trump Tariffs yield a similar outcome?
Links
Recession did not lower C02 emissions http://www.independent.co.uk/environment/climate-change/recession-did-not-lower-c02-emissions-6272333.html
Rapid growth in CO2 emissions after the 2008–2009 global financial crisis https://www.nature.com/articles/nclimate1332
Financial crisis of 2007–2008 https://en.wikipedia.org/wiki/Financial_crisis_of_2007–2008
Great Depression https://en.wikipedia.org/wiki/Great_Depression
Causes of the Great Depression https://en.wikipedia.org/wiki/Causes_of_the_Great_Depression
Smoot–Hawley Tariff Act https://en.wikipedia.org/wiki/Smoot–Hawley_Tariff_Act
The History of Carbon Dioxide Emissions http://www.wri.org/blog/2014/05/history-carbon-dioxide-emissions
Statistically derived contributions of diverse human influences to twentieth-century temperature changes https://www.nature.com/articles/ngeo1999
Steel and Aluminum Tariffs Could Add 2 Cents per Watt to Utility-Scale Solar Projects https://www.greentechmedia.com/articles/read/steel-aluminum-tariffs-could-add-2-cents-per-watt-to-utility-scale-solar