Weather, climate different

It’s 30 below. How can there be global warming?

Weather is not climate. Most climatologists believe year-to-year variations alone cannot be linked directly to a warming or cooling climate. It’s hard to tell much from a single cold spell or severe storm.

There is a difference between weather and climate. One working definition of climate is the average weather over at least a 30-year period. The 10 warmest years on the planet in recorded history have occurred since 1997.

Taking a longer term view, there is evidence the rate of warming seen recently is unprecedented in 1,000 years. Individual severe weather events are less meaningful than the trend of increasing numbers of these events over decades or longer.

Another thing to remember is we tend to pay attention to air temperature. This is what your weather app gives you; this is what the radio reports on the hour. More than 90 percent of global warming goes into heating the oceans compared to 2 percent into the atmosphere.

Any conversation about climate change has to include information about ocean temperature, something I’m often less aware of living here in the Midwest. Fifteen of the 18 years since the turn of the century have set records for highest average ocean temperature.

The January issue of Science magazine describes this in more detail. This trend will be important to follow to accurately measure climate.

Temperature is an objective measure and is fairly straightforward. We can do this incredibly precisely on a global scale, including in the oceans, maybe the most important measure of climate change. Short-term variation doesn’t tell us much. We need to remember our grade-school Earth science coursework: Climate and weather are not the same.

Lang Jacobson

Eau Claire