The climate is changing, which may be detrimental to the long-term future of your garden. You should begin to prepare for the increased variance in weather: abnormally warm or cold seasons, longer dry spells, more violent rains. I wouldn't worry about the total increase of temperature, if you live in temparate zones - it is predicted to be a mere few degrees over the next few decades, and your plants will probably enjoy it.
The largest climate-induced risk to your garden is probably potential breakdown of society in areas worse off than yours. I suggest you leave the resulting massive wave of migration to your government, which will probably sort out a nice border fence, and focus on things you can do something about.
So, let's learn about storing water.