The earth is a powerful organism, and I believe it can handle almost everything we have "messed up" to this point if we eliminate the problems that have caused damage. If we discontinue destructive behaviors, in most cases, things will clear up in time.
Technology will need to grow faster than our current rate of consumption and destruction. For instance, the creation of affordable alternative fueled vehicles would need to become a reality before we exhaust our petrolium supplies. At the moment, this isn't really happening. While new, greener technologies are being developed, they are typically far more expensive and less reliable. People will not be willing to switch until the new technologies are affordable, stable, and well tested.
I think one successful way to change our impact on the environment is to make it cheaper for businesses to produce and package goods in ways that are more environmentally friendly. Whether this requires new technology in manufacturing and packing or just changes in attitudes is a toss up. Look how CD packaging has changed over time. Much cheaper and much more environmentally friendly. Not too mention the invention the MP3 has completely revolutionized that same industry and made it much more environmentally friendly. What we need are solutions (particularly I think in packaging) that make it cheaper for the producer and that will allow savings to be passed on to the consumer. Toys have way more packaging (and in mostly non-recylable materials) than is necessary. If toy manufacturers could save money on packaging and still sell the same if not more products then we would see the trend move through the business and then on to other businesses.
The most likely solution is for us to invent new technologies. We need to create new technologies that use less energy. If we can do that, then we can mitigate the impact we are having. This is much more likely to succeed than efforts to simply make people stop consuming so much.