I've never understood how a christian person wouldn't understand this. It's all over the scriptures as far back as Genesis:

"And God blessed Noah and his sons, and said unto them, Be fruitful, and multiply, and replenish the earth."

I think people sometimes think "multiply and replenish" just means have babies - but that's just the multiply part. Replenish means to put back or restore to the former level or condition. This dude is right on the money. The scriptures are clear, and we're jacking up our stewardship of this planet.