Environmental Engineering Reference
In-Depth Information
After 2030
After 2030
After 2030
After 2020
2000
2020
2040
2060
2080
2100
2120
Figure 15.4
Predicted ranges for global crude oil peak according to 21 different studies examined by the
Government Accountability Office (2007).
proposed the conversion of the transportation fleet from petroleum-based fuels to natural
gas. It is claimed that the US gas reserves are enough to supply the country for 200 years
(GNGNow, n.d.). However, on a global scale, predictions indicate that natural gas will peak
almost at the same time as oil.
Other peaks
Water unlike oil and gas is a renewable resource. However, at regional levels there is a
maximum quantity of water that can be extracted at any time, which in a sustainable scenario
the rate of extraction would be lower or at least equal to the rate of replenishment. It is
happening in many aquifers around the world that the rate of extraction far exceeds the rate of
replenishment. Moreover, in the case of nonrechargeable aquifers, once the water is totally
pumped, it is gone for good. So, with the increasing level of water demand as population
grows, it is reasonable to expect that at some point, water extraction will peak at regional
levels and that peak will be equivalent to the rate of recharge by the hydrological cycle.
In contrast with nonrenewable resources, the best case scenario is that the allowable rate of
water extraction will plateau and remain constant. However, if climate changes, rates of
replenishment may also change and a bell-shaped curve as in the case of oil and gas could be
expected.
Phosphorus is limited in concentrated deposits and for practical purposes can be consid-
ered nonrenewable. The problem with phosphorus is that it has been taken from concentrated
deposits and then released to surface water bodies via runoffs from agriculture and through
municipal wastewater treatment. It is important to mention that humans excrete phosphorus
though urine that ends up in treatment plants and then in rivers and the ocean. Therefore, there
