First published at progresstrap.org
According to the U.S. Global Change Research Program*, "it is extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence."Excerpt from 2017 report, Executive Summary:

Multiple System Failures During Extreme Events
- Impacts are particularly severe when critical systems simultaneously fail. We have already seen multiple system failures during an extreme weather event in the United States, as when Hurricane Katrina struck New Orleans. Infrastructure and evacuation failures and collapse of critical response services during a storm is one example of multiple system failures. Another example is a loss of electrical power during heat waves or wildfires, which can reduce food and water safety. Air conditioning has helped reduce illness and death due to extreme heat, but if power is lost, everyone is vulnerable. By their nature, such events can exceed our capacity to respond. In succession, these events severely deplete resources needed to respond, from the individual to the national scale, but disproportionately affect the most vulnerable populations. (Source)
* 2014 National Climate Assessment. U.S. Global Change Research Program
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References:
https://science2017.globalchange.gov/chapter/executive-summary/
http://nca2014.globalchange.gov/highlights/report-findings/widespread-impacts