I work at an inland university in chilly upstate New York. Around here, many people feel a little global warming is good and there is really nothing that they can see or hear that will make them feel differently. News of warming sea surfaces and bleached coral reefs inspire little response when there’s a chill in the air and the ocean is hundreds of miles away.

Sure, the ice is off the lakes a few weeks earlier and the growing season is a couple of weeks longer. But there are costs we are seeing now — mosquitoes, ticks and other species of insects are really thriving with the warmer weather while some species of trees, like sugar maple, are suffering slow declines.

However, none of these small, incremental impacts gives one a sense of imminent disaster, but the reality is that increased sea-surface temperatures will impact hundreds of millions of people, whether they live in Key West or Kalamazoo.

In contrast to the incremental changes we are seeing here in the heartland, the sea is already undergoing catastrophic changes on a massive scale, ones that are unprecedented in human history and that may be largely irreversible on human time scales.

(Read more over @ CNN)