At this point in time, this statement is far from true. It may be that renewable energy sources such as wind and solar are the future, but petroleum and other fossil fuels are still the present (and are probably the near future as well). There are three main reasons for this.
First, although some scientists once believed stores of fossil fuels were dwindling, it now appears that this is not true. New technologies have made it feasible to exploit many more sources of fossil fuels. It appears that we have enough fossil fuels for decades to come.
Second, in order for fossil fuels to be the past, we would need something to replace them. At this point, we do not. We do not have alternatives that could provide as much energy as we need.
Finally, we would also need other alternatives to be cheaper than fossil fuels. At this point, they are not. Alternatives like wind and solar simply cost much more at this point than fossil fuels do. Until these technologies improve, fossil fuels will be more economical.
We should hope that the future will come soon so we can stop using fossil fuels and creating greenhouse gases, but that point is not here yet.