If anyone still doesn’t believe in global warming, come to Glacier National Park.  My wife Karin and I just spent two days of our vacation here.  We haven’t been here in 20 years, and first visited about 30 years ago.  It’s a majestic wonderland, and from what I’ve seen, it’s probably the most spectacular mountain scenery in the lower 48 states.

Glaciers carved out this scenery millions of years ago, and glaciers still exist here today.  When first seen by early explorers a little more than a century ago, 136 glaciers were identified, named, and documented in the Glacier National Park area.  Today, there are 25 left.  For the past 15 years, one glacier has been lost annually.

Karin and I reached Logan Pass, the summit of the famous Going to the Sun Road.  We stopped at the Visitor’s Center and listened to a talk by a National Park Ranger on the glaciers.  Scientists studying the retreat and melting of the glaciers originally estimated that all the glaciers in Glacier National Park would be gone by 2030.  Now they have revised that estimate to 2020, 11 years from now.

It’s true, the ranger explained, that there have been some “normal” cycles of warming and cooling over many thousands of years affecting things like glaciers, icecaps, etc.  But the rate of glaciers melting in this park is unnatural and unprecedented, faster than at any time known in history.  It is clearly the result of the burning of fossil fuels, and human actions raising the earth’s temperature.

But here’s the thing.  For Karin and me, this is personal experience.  We remember visiting Glacier National Park when our son was a toddler—probably 2 or 3—and our daughter was an infant. (Today, they are 25 and 27.) We were with our brother and sister-in-law.  At Logan Pass, we hiked out on the trail.  J.K., our son, was on the shoulders of his uncle Dan.  Karin and I remember what the glaciers looked like.  We recalled where the snow and ice were.  We knew vividly what Jackson Glacier looked like at the time, and others.  And the difference in what we saw this past Monday was stunning.

It’s one thing to talk about global warming as a theory.  It’s another thing to be some place where you can see and experience its effects first hand. I began working on the threat of global warming, and the response of Christians, when I started my service with the World Council of Churches in 1988.  There were plenty of skeptics at the time.  But today, most recognize how the human causes of climate change are an assault on the gift of God’s good creation, and a betrayal of our biblical responsibility to serve as stewards and earth-keepers.  Yet, in the two decades since then, the glaciers have been melting faster than ever.

Last month the House of Representatives passed legislation to address climate change.  It calls for a 17 percent reduction of greenhouse gases by 2020 (when the last of the glaciers I saw Monday would be gone), and 83 percent by 2050.  My friends who follow this closely, like Jim Ball of the Evangelical Environmental Network and John Carr at the U.S. Catholic Conference, worry that its provisions are not strong enough, and that funds to assist developing nations to make adaptations in their greenhouse emissions are completely inadequate.  Even so, lobbyists are pushing to significantly weaken what the Senate will pass.

Members of Congress are going home for the August recess.  Why not send them to visit Glacier National Park?  Examine the evidence.  Melting glaciers are like the canary in the coal mine.  In the end, this isn’t about scenery.  It’s about survival, especially for the poor and vulnerable, who have the least defenses and will be the most seriously affected by the patterns of drought, rising sea levels, and intensification of hurricanes that result from climate change.

Wes Granberg-Michaelson is General Secretary of the Reformed Church in America.