The estimates I've seen mostly suggest damages in the range of 0.5-10% of GDP https://www.brookings.edu/research/ten-facts-about-the-econo...

Here's a quote from the IPCC consensus report: "For most economic sectors, the impact of climate change will be small relative to the impacts of other drivers (medium evidence, high agreement). Changes in population, age, income, technology, relative prices, lifestyle, regulation, governance, and many other aspects of socioeconomic development will have an impact on the supply and demand of economic goods and services that is large relative to the impact of climate change." https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-Chap...

Another IPCC quote: "Under the no-policy baseline scenario, temperature rises by 3.66°C by 2100, resulting in a global gross domestic product (GDP) loss of 2.6% (5–95% percentile range 0.5–8.2%), compared with 0.3% (0.1–0.5%) by 2100 under the 1.5°C scenario and 0.5% (0.1–1.0%) in the 2°C scenario." https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-Chap...

Dunno. Seems like the oceans are dying. Ever more efficient fishing, acidification, and increasing pollution are taking a heavy toll. The ocean based food web might just collapse. Countries that depend on the ocean for food will get less stable and food prices will rise. Farms are increasingly penned in by developments, and when the weather changes enough for the new ideal areas for farms, will likely to be over developed already. Farms placed poorly will have more crop failures, and spend more energy in attempt to mitigate lack of water, healthy soil, lack of sun, extreme weather events, etc.

Bees might well not survive, complicating any farming that depends on them. Rain is becoming more acidic, making it harder on plants.

Seems like many scientists are ringing alarm bells, even if we aren't sure what the world will look like in 20 years, seems like a bad idea to roll the dice and hope for the best.