Short answers, pulled from the story.
The British government commissioned the Stern Review in 2006 to quantify the economic scale of climate change damages. Nicholas Stern led this project which linked features of society and economy with the biosphere and atmosphere into one modelling framework.
A temperature rise between 1960 and 2019 cut current GDP per person by 18%. A one-degree increase in global temperature reduces global GDP by 12% while an increase of three degrees by 2100 could reduce capital by 50%.
Direct losses from disasters averaged above US$330 billion annually between 2015 and 2021. One study estimated global losses to average US$143 billion per year between 2000 and 2019 including a statistical loss of life value of 90 billion and economic damages of 53 billion per year.
The International Labour Organization published a report titled Working on a warmer planet in 2019 claiming that even if temperature rise is limited to 1.5 degrees, climate change will cause productivity losses reaching 2.2% of all working hours every year by 2030. This loss is equivalent to 80 million full-time jobs or 2,400 billion dollars.
William Nordhaus defines his discount rate to be the rate of return on capital investments around an average of 4%. Nicholas Stern takes a prescriptive approach where zero pure rate of time preference indicates all generations are treated equally leading to long-term discount rates of 2 to 3% in real terms.