Today, my friendly neighborhood Potbelly Sandwich Shop posted small flyers along the ordering line, asking: “Where are the tomatoes?” The flyer explained:

The recent cold weather across North America has had a severe impact on the availability, quality and cost of tomatoes.

Due to these factors, we will temporarily cease to offer tomatoes on your sandwich. As soon as the tomato crop returns to normal we will add them back to your sandwiches.

We apologize for this inconvenience. We do not want to compromise on the quality or value of our sandwiches.

More evidence — if any were needed — that winter endangers public health and welfare. Tomatoes are a great source of anti-oxidents and other health-enhancing nutrients. And they are delish!

Besides ruining tomatoes, winter is strongly correlated with cold and flu. Winter can also cause or contribute to power outages, travel disruptions and delays, traffic accidents, and injuries from slipping on ice.

You’d think that by now global warming would have made harsh winter weather a thing of the past. Alas, no. Our tomatoes, and the health and welfare benefits they bring, are still endangered.

But be of good cheer. The carbon dioxide emissions allegedly responsible for Al Gore’s “planetary emergency” are helping tomatoes beef up. The Center for the Study of Carbon Dioxide and Global Change maintains a database on field and laboratory experiments measuring plant growth response to CO2-enriched environments. Here’s the link for data on tomatoes.

A whopping 45 studies have examined the effects of CO2 enrichment on the garden tomato (lycopersicon eculentum). On average, garden tomatoes gain 32.6%, 40.9%, and 46.8% additional dry weight biomass, respectively, when grown in air containing an extra 300, 600, and 900 parts per million of CO2.

In light of both the cold-induced tomato scarcity at Potbelly’s and the mass-boosting effects of CO2 enrichment, it would appear that tomatoes may survive global warming after all.