Start planning for +6C. We'll blow past 2C in the decade, 4C in a couple decades, and on up to 6C shortly thereafter. With the Arctic ice collapsing, it will warm even more in the summer and freeze less in the winter. Wave action will get stronger and further prevent ice from forming. The 20C increase in Arctic temps will cause unknown changes in weather patterns. We're already bouncing the jet stream around. Every prediction about climate warming has come true faster than expected. The current trend - regardless of Paris - is to continue burning fossils. China is making some progress but more to cut visible pollution than the reduce greenhouse gases. If Trump and company do destroy the Paris Agreement, not much will stand in the way of rising temps.
That said, we must still work towards replacing fossil fuels. Documents from much more knowledgeable people outline plans to replace fossil fuels with renewable energy by the end of the century or sooner. They also make a reasonable business case - especially if fossil subsidies are removed and we charge fossil users to throw away their trash.
"Big Oil" companies have a sporadic record of investing in renewable energies. A few reasons are given but the result is currently the big oil companies don't have much incentive to invest in renewables. That needs to change. If Big Oil becomes "Big Energy" - invested in all forms of generation and storage - it can remove itself from the lobbying for it's own economic well being. No matter what energy we favor, they will be able to capitalize on it. One big cause of deniers will be removed.
Look for the Alt Radical Left to force users to pay for throwing out their trash when they burn fossil fuels, eliminate government intervention in supporting fossil fuels, and encourage energy companies to expand their portfolios. Please feel free to let me know about other ideas. It is too late to stop some dramatic global warming but these steps are necessary anyway.