All these things are tiny impacts. If all humanity disappeared today, in 100k years, there would be almost no trace of us left. The planet would continue on as if we were never here. It isn't that we can't make any changes, it is that it will have almost no impact on the future. This solar system is estimated to have the sun burn out in 4 billion years from now. You are confusing landscaping with permanent change. We can affect small areas of the planet and can influence minute changes. We do not have the ability to match the amount of energy required to cause permanent changes to large areas. The effects may last decades, or centuries, but when you expand your vision to millennia, you see how insignificant humanity still is.

I don't think there was enough human population in existence to have decimated an area that large. There doesn't seem to be any evidence of large scale human habitation in the region of the sahara. How could human beings have achieved such long lasting effects on the region. Forest fires have completely burnt to ash millions of acres of forests and yet the forest returns in a matter of years. How do your think it possible that we destroyed the entire eco system of North Africa with a relatively small number of human beings, 11000 years ago? How could they have altered the weather patterns to reduce rainfall to desert levels? No evidence of large scale human habitation, no real idea of the cultural or technological capability of human beings at that time. Don't you think that it is possible that at the end of the last ice age there is a more likely scenario that the Earth was undergoing some climate changes that resulted in changes of how rain, winds, seasons affected many different regions in the world? The climate of an area might be considered a region averages of 30 years, but that is to come up with some sort of standard for that area. The changes of climate within any localized region can stay relatively constant for thousands of years or can make relatively large changes in a relatively short period of time. The point is that human beings can come in and burn down thousands of acres of land and it will have no affect on the climate on that area. The climate will still allow regrowth of trees in the area. Yhe rains will still fall. The forests will regrow and plants and animals will return. In order for nothing to regrow in the area, the climate has to change. We can even sterilize the soil and it will make no difference. The soil will be reseeded with micro organisms over a relatively short period of time. Look at the eruption of Mt. St. Helens. This is a very recent and very well documented total devastation event. Look at how quickly the area reseeded and restored itself to how it was before the eruption. Look at the Bikini atolls after we detonated a massive nuclear explosion. Those islands were shockingly reseeded and animals now thrive on those islands and all of that happened after complete an total annihilation of the islands in the 1950's and the restoration tool less than 10 years, scientists believed that it would be uninhabitable for thousands of years. The same for the massive forest fires every year in California, Canada and the Pacific Northwest. Most of these fires are started by arson. The funny part is that it overwhelmingly started by Climate activists who are so desperate to be heard that they burn millions of acres of forests to "save the planet". These people have taken the climate change brainwashing to ridiculous levels. The most impressionable short-sighted and completely self involved narcissists that thinks they are going to rescue mother Earth from evil humanity. I hate to tell them, but we are animals within the eco system. Whatever we do is a part of nature. We are not separate from nature, we are a part of it. If we developed through evolution, then we are a piece of what nature has created. However we change the environment is a part of nature and not different than coral building reefs, or ants excavating their warrens and nests or even swarms of locusts that decimate huge swaths of land every so often. The only way we could be an invasive species is if we were placed here instead of having being evolved here. Of course, there is the other view point that God made this Earth for us and told us to appreciate it and take care of it. Either way, we belong here and we are a part of this planet. I am not disagreeing with the idea of conservation and husbandry, but I am saying that people need to understand that we can't stop the Earth from entering a new ice age. We can't stop the Earth from changing. Everything changes and everything dies. We are not siginificant enough to change the Earth. We don't have enough power. Consider this; one hurricane in the Atlantic ocean has more energy than all of our nuclear weapons combined. Our most powerful and destructive force we have ever created and Nature makes a series of them every single year. One earthquake has more energy than we create in a year. One volcanic eruption, one massive lightning storm. We truly are paltry and weak organisms compared to the massive power and glory of this planet. And this tiny planet is dwarfed by our sun in this backwater solar system within a massive galaxy. To even contemplate our place in the Universe among millions of galaxies is unimaginable. We can't even control the weather in one square block, let alone a square mile. To think we can change the climate of an area over the insignificant number of 30 years is almost laughable. We can plant trees and bushes and flowers to help shape nature in an area, but if the rain doesn't come, we either have to irrigate to continue the growth or it dies. We can't make it rain and we can't make it stop. We have tried seeding clouds with limited success, but these are things we have to actively continue to interfere with. As soon as we stop investing energy, the planet goes back to doing what it does. We are the ones that adapt to the planet, not the other way around. At some point, the Earth will enter another ice age. We don't know what drives the cycle, we just know that it happens. We didn't create a warming trend, and we won't be able to stop the next cooling trend. CO2 has never been shown to affect a warming trend or a cooling trend. It is always a result of changes in climate, not the other way around.