Rainforests also exist in temperate regions where forests receive more than 200 centimeters of precipitation per year. These temperate rainforests are a rare ecosystem, occurring on only one-half of one percent (0.5%) of the land area of Earth even prior to their recent destruction.

Temperate rainforests occur in the northwest US and Canada, from northern California to Alaska; in southwest South America, along the west coast of Chile; in Australia, Chile, the US, Canada, Alaska and Australia are being heavily logged for timber and pulpwood for making paper.

Temperate rainforests have very high levels of biodiversity compared to other temperate forest ecosystems. The climate of these areas tends to be more even and temperate due to their proximity to warmer coastal waters. For instance, temperatures along the coast of the northwest US tend to be much warmer than the interior at the same latitude. These more mild year-round temperatures have allowed evolution to more quickly speciate — that is, to evolve unique species, even though in general, these ecosystems did not exist prior to the retreat of glaciers about 12,000 years ago.

While these forests are relatively young compared to tropical rainforests, they are vital for a number of reasons.

Temperate rainforests regulate climate and water cycling. As well, temperate rainforests support some of the oldest trees in the world (which are, in fact, some of the oldest living organisms on Earth). There are three species of redwoods in the world, two of which occur in the northwest US, sequoias and California (coast) redwoods, and one in China, the dawn redwood. These trees are the largest living organisms on Earth. Redwoods can grow to nearly 300 feet and sequoias can attain a diameter of 29 feet.

Douglas firs, western red cedars, Alaskan (yellow) cedars — these trees can typically grow for 1,800 years or more. Most of these big giants have been cut long ago. Some 1,200-year-old redwoods still exist in protected remnant groves. However, logging companies continue to hammer away at these temperate rainforests.

For more on temperate rainforest woods and the companies logging them, see the What to Avoid section, Temperate Woods.