I think that in 2100, it will be very good if we take a priority in developing advanced biotech and nanotechnologies that will enable us to recycle all our waste back into product and most important, will enable fix our aging cells that means make old people young again. Also I think it will enable the most green environmentally based on high-nanotech in the future you could imagine such as see the foresight institute, they started the nanotech revolution essentially.