how has human impacted on the carrying capacity
The use of fossil fuels has artificially increased the carrying capacity of the world by the use of stored sunlight, albeit at many other expenses.
The earth is our island. We have an advantage over the rabbits in that we have developed technology to grow, process, and store food so that we can survive the bad years. We have also developed technologies for handling wastes that we create. However, there is still a carrying capacity that the earth can support. That carrying capacity is a function of the number of people, the amount of resources each person consumes and the ability of the earth to process all the wastes produced. Sustainability is about finding the balance point among population, consumption, and waste assimilation.