The Extremes Become the Norm

The report argues that climate change shifts the probability curve of temperature and precipitation, making once-rare extreme events common. It highlights that while a 4°C rise in average temperature may seem small, it significantly increases the likelihood of deadly heat waves and catastrophic floods. The document cites specific examples from the United States, Russia, and Australia to illustrate the economic and social risks, attributing 90% of global warming to human activity and urging immediate emissions reductions and adaptation measures.

• A small shift in the average global temperature results in a significantly higher frequency and intensity of extreme high temperatures and a lower frequency of extreme low temperatures.
• In the United States, July temperatures are rising; the average July temperature for this century is 75.5°F, which is more than 1 degree warmer than the 20th century norm of 74°F.
• Climate projections suggest that by the end of the century, some areas in Texas that typically see 10-20 days over 100°F annually will experience such temperatures for nearly four months every year.
• The probability curve for rainfall is expected to flatten and shift, increasing the likelihood of both extreme droughts and major floods.
• Human activity is responsible for 90% of global warming over the last 250 years, with carbon dioxide concentrations surpassing 400ppm for the first time in human history in May 2013.
• The economic impact of natural disasters is increasing, with worldwide costs reaching a record $380 billion in 2011.

APA

Aggarwal, S., & Kennan, H. (2013). The Extremes Become the Norm. Energy Innovation. https://energyinnovation.org/wp-content/uploads/extremesbecomenorm_finalupdate1.pdf

Chicago

Aggarwal, Sonia, and Hallie Kennan. The Extremes Become the Norm. Energy Innovation, 2013. https://energyinnovation.org/wp-content/uploads/extremesbecomenorm_finalupdate1.pdf.

Wikipedia

{{cite report |last1=Aggarwal |first1=Sonia |last2=Kennan |first2=Hallie |title=The Extremes Become the Norm |publisher=Energy Innovation |date=June 2013 |url=https://energyinnovation.org/wp-content/uploads/extremesbecomenorm_finalupdate1.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{aggarwal2013extremes, author = {Aggarwal, Sonia and Kennan, Hallie}, title = {{The Extremes Become the Norm}}, institution = {Energy Innovation}, year = {2013}, month = jun, url = {https://energyinnovation.org/wp-content/uploads/extremesbecomenorm_finalupdate1.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }