Here’s an example of strong linear positive correlation: greenhouse gas emissions and unstable climate.

An equation: Unstable climate - rising sea levels, increasing temperatures, more severe hurricanes - is equal to massive migration, economic catastrophe, environmental degradation and harm to human health.

That’s the math lesson McKinsey & Co., the largest consulting firm in the world, is trying to teach CEOs right now.

Climate change will do substantial damage to the world’s economies, wreaking havoc on communities and economic activity across the globe, a new report, produced by McKinsey’s internal think tank on climate change, reminds its Fortune 500 clients. Assuming no decrease in emissions or efforts by communities to protect themselves from climate change, the next 10-30 years will be devastating for communities around the globe, putting hundreds of millions of lives and trillions of dollars in economic activity at risk.

The Southeastern and Gulf Coast regions of the United States will be among the hardest hit by the physical effects of climate change, researchers write, as precipitation of severe hurricanes may double along the U.S.’s southern coasts and temperatures will almost certainly rise.

On HoustonChronicle.com: Economies need major climate adaptation or risk “substantial” damage

A separate report, by researchers at the University of Texas published this month as well, found that the shale boom in Texas, through increased production and the expansion of petrochemical and other processing plants, stand to add 178.7 million tons of greenhouse gases into the atmosphere per year by 2030.

The transition away from coal toward natural gas for power generation has lowered the carbon intensity of electricity in the U.S., but the math still doesn’t look good. In Texas and Louisiana combined, annual new oil, gas and petrochemical plants emissions will equal that of 131 coal-fired power plants by 2030, the researchers estimate. The petrochemical industry in Texas alone is set to make up 60 percent of the increase in the industry’s emissions in Texas.

Still, even if all the oil, gas and petrochemical plants were shut down tomorrow, decades of greenhouse gas emissions are already “locked into the system,” as Dickon Pinner, senior partner at McKinsey, who headed the firm’s recent research initiative, pointed out to me. Climate change has become a risk management problem because it’s much more difficult to eliminate the systemic risk - a.k.a. eliminating reliance on fossil fuels.

That means Texans can invest in climate resilience, preparing our homes, businesses, cities from the physical catastrophe climate change has and will bring, or we can take our chances.

In a way, the problem (the choice of whether to reduce emissions and prepare today, or to do nothing) reminds me of a conversation I recently had with Tom Luce, a long-time Texas politician and lawyer, who is now working on state education reform. He uses a very simple equation to make his case: The economy needs increasing population and productivity to grow. Texas’ population growth is slowing, he said, and unless we fix the state’s failing K-12 education system — for which Texas has done practically nothing to improve since the 1980s — declining productivity growth is going to drag us down, too.

“It’s math,” he says.

True, and so is climate risk. But Texas doesn’t seem to be all that good at math. Maybe it’s because the state’s inspiration for its economic booms - oil wildcatters - often made it on complete luck… and faulty math. Their odds were bad and inadvisable, but they struck it rich anyways. (In busts, many struck it poor later.)

The Intergovernmental Panel on Climate Change, the UN’s governing body on the issue, puts 2020 as a turning point year in which the effects of climate change will begin to escalate or mitigate depending on how how much greenhouse gas emissions are reduced and how well prepared communities adapt and innovate. Texans will need to decide this year — this decade — if we are going to heed the math or take our chances.

erin.douglas@chron.com

Twitter.com/erinmdouglas23