July was the hottest month on record in the continental U.S., according to the National Oceanic and Atmospheric Administration (NOAA). The temperature was 3 degrees above average. The last 12 months have been the warmest since they began keeping records back in 1895.
"On average, temperatures have been rising all over the globe, and that's certainly true, and it appears in all kinds of data sets, and there's no way around that," said Julien Emile-Geay, an assistant professor in the USC Department of Earth Sciences.
A new report by NASA scientist James Hansen studied temperature variations. Hansen says these weather changes aren't random or normal. He claims it is climate change.
NASA animation shows temperatures over the last 130 years. An above-average warming trend can be seen over the last 30 years in sections of the Northern Hemisphere of the Earth.
"One of the expected consequences of climate change in regions like Southern California is that it will become drier. So the meteorological extreme that we are the most vulnerable to is drought," said Emile-Geay.
Report author Hansen has called for the U.S. government to regulate greenhouse gases. There is still disagreement over the issue of global warming. Some scientists do not believe there's a link between extreme weather and climate change.
"The one thing that is controversial is whether you can blame a single weather event on climate change. That, you cannot," said Emile-Geay.