Climate Change is Happening

Each graph below links to a paper with more detailed information.

Summer_Winter Temps(Deviation from mean 1951-1980 climate)

The charts shows that summers have become noticeably hotter.  The shift in winter is less obvious, even though the average warming is comparable to that in summer, because of greater natural variability in winter. Click the graph to download the paper “Perception of Climate Change” to learn more.




Carbon intensity, defined as fossil fuel carbon emissions (GtC) divided by energy consumption (Gt of oil equivalent). Energy intensity of China is normalized to 1.56 that of the United States in 2005. Click on graph to download Dr. Hansen’s opinion piece: “Renewable Energy, Nuclear Power and Galileo: Do Scientists Have a Duty to Expose Popular Misconceptions?” to learn more.


The industrial revolution began with wood being replaced by coal as the primary energy source. Coal provided more concentrated energy, and thus was more mobile and effective. We show data for the  United States because of the availability of a long data record that includes wood. More limited global records yield a similar picture (please see figure 14 in the paper). Economic progress and wealth generation were further spurred in the twentieth century by expansion into liquid and gaseous fossil fuels, oil and gas being transported and burned more readily than coal. Only in the latter part of the twentieth century did it become clear that long-lived combustion products from fossil fuels posed a global climate threat.

Click on the graph to download the paper Assessing ‘‘Dangerous Climate Change’’: Required
Reduction of Carbon Emissions to Protect Young People,
Future Generations and Nature” to learn more.



1913 to 2013 annual-mean global surface temperature change based on the local linear trends. Click on the graph to download  the paper “Global Surface Temperature Change” to learn more.