It's not easy being green, at least not as easy as some suggest.

For almost 40 years, advocates of Earth Day have called on people to celebrate environmental progress and to protect our planet. To this goal, Christians can say a hearty "Amen, but..."

"Amen," because we should certainly strive to preserve, protect and sustain our earthly home. Such good intentions fit well with the biblical call to exercise responsible stewardship of God's good creation.

But good intentions aren't enough. Without wisdom and sound judgment, they can lead to harmful, unintended consequences--harmful not just to the environment, but to the world's poor, whom we are also called to care for and protect.

The concept of stewardship involves taking care of something that belongs to somebody else. For Christians, stewardship of the environment recognizes that "the earth is the Lord's and the fulness thereof" (Psalm 24:1). Creation belongs to the Creator. The Christian tradition affirms that humans have been given the privilege and task of tending and cultivating it for good.

Over the past several decades, creativity, ingenuity and innovation have generated important improvements in the well-being of the earth and human life. Around the globe, death rates have declined as the quality and quantity of shelter, food, clothing, health care and hygiene have increased. In developed cities, smog levels have been falling as living standards have been rising. There is much to celebrate in terms of positive human stewardship of the earth's resources.

Sadly, though, these conditions are not experienced in many regions. In some parts of Africa, for example, water is contaminated, air is polluted, and diseases are rampant. These are problems we know how to solve. But, for various reasons (war, stagnant economies, political corruption, etc.), squalid conditions remain. There is much to lament in terms of poor human stewardship of the earth;s resources.

We can approach Earth Day ready to celebrate the good (and commit to improving the not-so-good) effects of human use of the earth. For Christians, this day can serve as a reminder of the calling to be good stewards not only of the land and seas but also of the crown of creation: fellow human beings, especially the poor among them. Such a responsibility, though, means more than being motivated by good intentions. The task of stewardship is not that simple. It also requires that we ask about the real consequences that our well-intended actions produce.

This is true not only in our daily lives at home and work, but also in the response we ask from government. Clouded--indeed, polluted--judgment is often magnified when it receives the backing of law. Prudence is essential for making sure good green intentions don't lead to counterproductive regulations. In other words, good stewards are good students--pupils of policy who do their homework regarding what works and what doesn't.

Practices that actually generate worse suffering among people cannot be justified as good stewardship. Yet too often this is what happens in the name of environmental protection.

Take, for example, mandates concerning ethanol, which have raised the price of staple food prices around the world. The intentions might have been good, but this policy has actually hurt many nations and people suffering from hunger.

Or consider bans against the use of pesticides like DDT in some African and Asian countries. Such policies have actually led to the resurgence of malaria in those countries, causing over a million premature deaths each year.

The poor and vulnerable will also be disproportionately affected by costly cap-and-trade policies that regulate carbon emissions in the name of fighting global warming. The change in global temperature such policies are expected to bring about is miniscule--less than half a degree Celsius; the cost in terms of energy bills and lost jobs, however, is great. Because low- and fixed-income families spend a greater portion of their disposable income on fuel, policies that raise energy prices will hit them the hardest.

Such examples show that we need to be good stewards of our good intentions, making sure that we do not actually do more harm than good to the earth and its inhabitants. Being good stewards--and students--of the environment means taking the time to explore how real people are affected by the choices we make. It means understanding what has actually led to cleaner air and water. It means acknowledging the benefits of responsible human productivity. It means affirming the ways in which economic development has led to cleaner technologies and increased standards of living for the poor.

Responsible stewards say "Amen" to green goals. But they know that sometimes a yellow light is needed to prevent hasty actions with harmful effects.

Ryan Messmore is the William E. Simon Fellow in Religion and a Free Society at The Heritage Foundation.