It seems that many environmental scientists paint a picture that depicts the natural world as being ideally static, i.e. the current climate is the ideal and shouldn't change, the current flora and fauna must remain at sustainable levels, etc. Natural history paints a totally different picture, the climate has been both warmer and colder, flora and fauna have come and gone, long before there was any human influence. Human beings are currently the dominant species on the planet but that could change at any time. We could kill of ourselves by nuclear war, nature could kill us through some kind of pandemic, natural disaster, or astronomic event. However, it should be remembered, we are a natural part of the Earths environment.
We collectively have a large impact on the environment around us, that fact can't be denied. We have killed off previously thriving species and damaged the population of others possibly to the point of unrecoverable population loss. What is the solution? In the US and Canada our reproductive rate has slowed to the point equilibrium or even slow population decline. The population increase we see here is mostly because of immigration. We can't close our borders, we can't force our policies on the worldwide centers of population growth by forcing birth control. About all we really can do is wring our hands and complain about population growth and how unsustainable it is.