Rising CO2 Concentrations: No Measureable Impact on Floods, Droughts, and Storms

Climate campaigners and their media allies routinely attribute extreme weather to anthropogenic global warming. Some more cautiously assert that a particular flood, drought, or storm is “consistent” with what global warming “looks like,” insinuating that carbon dioxide (CO2) emissions from fossil-fuel combustion must be to blame.

In Extreme Weather Events: Are They Influenced by Rising CO2 Concentrations?, Craig Idso of the Center for the Study of Carbon Dioxide and Global Change tests such claims against the empirical evidence contained in literally hundreds of studies of floods, droughts, and storms.

Idso looks at studies of extreme weather in numerous countries on several continents during the ~70-year period from the end of WWII to the present, when three-fourths of the increase in atmospheric CO2 concentrations above pre-industrial levels occurred. He also reviews paleo-climatological studies enabling researchers to compare current weather patterns with those occurring centuries and even millennia before the present.

The evidence Idso compiles is overwhelming. Here are the conclusions from the 79-page report’s three main sections:

Floods

Multiple researchers have investigated how flood activity has changed over the recent past and how this extreme weather event has responded to the global warming of the past several decades. Their analyses provide a means of evaluating climate-alarmist claims that CO2-induced global warming is leading to more frequent and intensified flooding around the globe; and they indicate there is nothing unusual about the flooding of the modern era. Large flood events occurring in recent times have many historic analogs in the past, when air’s CO2 concentration was much lower than it is presently. Taken together, the material presented in this section strongly suggests that rising atmospheric CO2 is having no measurable impact on modern flood events.

Drought

Like floods, many researchers have investigated how droughts have responded to the global warming of the past several decades. This section highlights the results of numerous empirical data analyses that shed light on the climate-alarmist claim that CO2-induced global warming is leading to more frequent and intensified drought events around the globe. These studies clearly indicate there is nothing unusual about drought events of the modern era. The large droughts that have occurred recently have many historic analogs that occurred during times when the atmosphere’s CO2 concentration was much lower than it is currently. Taken together, these materials suggest that the ongoing rise in atmospheric CO2 is having no measurable impact on modern drought events.  

Storms

Several researchers have investigated how storms have responded to the global warming of the past few decades. This section highlights the results of numerous empirical analyses that shed light on the climate-alarmist claim that CO2-induced global warming is leading to more frequent and intensified storm events around the globe. The studies discussed here clearly indicate there is nothing unusual about storms of the modern era. Severe storms of the most recent decades have historic analogs in the distant and not-so-distant past, when the atmosphere’s CO2 concentration was much lower than it is presently. As such, the materials presented below do not support the climate-alarmist contention that the ongoing rise in the air’s CO2 content is having a measurable impact on extra-tropical (non-hurricane) storms.