Government report acknowledges Hurricane Harvey made worse by climate change

A new climate-change report by the U.S. government offers little doubt that Hurricane Harvey’s catastrophic rainfall was worsened by rising global temperatures.

Citing Harvey and the 2017 Atlantic hurricane season, the new report acknowledges that the severity of the storms that devastated Texas, Puerto Rico and Florida were “consistent with what might be expected as the planet warms.”

Compiled with the help of 13 federal agencies and some 300 scientists, the Fourth National Climate Assessment notes that climate change intensified both the rainfall and rapid development of last year’s major storms.

“…the ability of four hurricanes — Harvey, Irma, Jose, and Maria — to rapidly reach and maintain very high intensity was anomalous and, in one case, unprecedented,” the report states. “This is consistent with the expectation of stronger storms in a warmer world.”

The report goes on to touch upon the relationship between rising temperatures and Harvey’s extreme rainfall, which reached an average of 51.88 inches before gauges broke and stopped recording rain amounts.

READ MORE: Government climate report warns of worsening US disasters

“Harvey’s total rainfall was likely compounded by warmer surface water temperatures feeding the direct deep tropical trajectories historically associated with extreme precipitation in Texas,” the report reads, “and these warmer temperatures are partly attributable to human-induced climate change.”

One study cited by the climate change assessment estimates that heavy rainfall from storms and hurricanes increased an average of 6 to 7 percent in the past century.

Elsewhere in the report, authors point out that the warming planet isn’t the only factor that made Harvey more deadly. The federal climate change assessment echoes the findings of a ProPublica and Texas Tribune investigation that predicted runaway land development would risk increased flooding.

“In the area affected by Hurricane Harvey, regional land management practices over the last several decades have reduced the area covered by wetlands, forests, and prairies, which historically absorbed stormwater runoff,” the report states. “These natural environments have been increasingly replaced with impermeable surfaces, decreasing Houston’s resilience to flooding.”

Fernando Ramirez is a digital reporter for Chron.com and Houstonchronicle.com. Read him on our breaking news site and on our subscriber site. Follow him on Twitter at @fernramirez93 or email him at Fernando.ramirez@chron.com.