Scarcity of oil and rising petroleum prices, and climate change driven drought, are a big deal. But there are fairly clear paths by which our society can adapt to both. Neither would be apocalyptic, even though it would drive significant, visible changes in our day to day material culture.
These matters are particularly worth thinking about on Earth Day, which is today.
Oil
A very large share of all petroleum consumption is for transportation, mostly cars, trucks, construction vehicles, boats, ships, and trains. Advances in battery technology, and EV manufacturing and infrastructure are making electric vehicle alternatives to all of those technologically viable. And, advances in renewable energy and nuclear power can replace almost all of the fossil fuels in the electrical power grid. Coal is well on its way to be phased out in the United States and much of the developed world. Alaska and Hawaii are the only U.S. states where a significant share of electricity is generated from petroleum. Heat pumps are paving the way as an alternative to heating buildings that were historically heated with heating oil in the U.S. (mostly in the Northeast).
Heat pumps and evaporative coolers (together with better insulation) also dramatically more energy efficient than conventional air conditioning, and renewables like solar and wind combined with modern batteries are particularly well suited to meet the demand for electricity to provide cooling.
Lots of fertilizers that are petroleum based could also become unaffordable, as they have as global petroleum supplies have been interrupted by U.S. and Israeli attacks on Iran, and its counterattacks. But organic farming techniques are now well established enough that these methods pose an obvious alternative path for agriculture is petroleum based fertilizers cease to become economically viable. Dutch models of intensive hydroponic agriculture suggests another off ramp from what is now considered conventional agriculture.
There are some applications where there aren't good alternatives to petroleum, like plastics and jet fuel. But these are such a small share of total petroleum consumption that these uses could be sustained, even if they become more expensive, even if petroleum prices soar and the supplies contract greatly.
Of course, plastics and petroleum based fabrics like nylon, have only been in wide use for about sixty years. If plastic becomes too expensive, we can revert to using metal, glass, wood, and plant and animal fiber alternatives for applications like kitchen ware and trash bins that aren't uniquely suited to plastic, as traditional alternatives becomes more affordable relative to plastic with rising petroleum prices.
The changes wouldn't be geographically neutral. A collapse in demand for petroleum driving by electric vehicles and organic farming would crush the economies of petrostates in the Middle East, in Brunei, in Nigeria, in Venezuela, and in select states within the United States. West Virginia has already seen its coal based economy collapse, as have many historically coal mining economy based regions in Europe. Wyoming will follow suit.
On the other hand, rare earth rich areas who supply key components of modern batteries and electronics, may see mineral economy booms.
Water
In most of the arid west, marginal agricultural activity consumes 80%-90% of all fresh water, while landscaping and golf courses consume about half of the rest of the fresh water. If water becomes scarce, entire regions can eliminate their water hungry landscaping, golf courses can close or become much more expensive or use artificial grass, and marginal agricultural operations can close.
In places like the Arabian Peninsula, Greece, Utah, and California, desalination technology might become more prominent as a water source, at least for high value municipal waters uses like drinking, cooking, and bathing, and gray water systems would use non-potable water (such as salt water from the ocean or salt water lakes) in applications where drinkability wasn't important, like flushing toilets.
Climate change that produces global warming ultimately both gives and takes away arable land. It renders much of the arid West unsuitable for farming and ranching, but makes places that were too cold for farming in the past, more suitable for it. Even when climate change doesn't actually change the total amount of arable land somewhere, it may change the kind of agriculture that is appropriate in that place.
Places that used to support subtropical orange groves may freeze more often and get dryer and become more suitable for cotton and the soft wheat varieties currently grown in places north of Florida in the American South. Crops now grown in the South might start to be grown in the Midwest. The abundant corn and wheat fields of the Great Plains and Midwest might move north to Canada. The Great Plains might transition from grain farming to cattle grazing.
I'm not a climate scientist. I don't have exact models of exactly when and where climate zones that are suitable for particular crops and livestock will relocate. But that's the basic concept.
The ongoing wars across the Sahel of Africa illustrate how ugly the process of having herders ecologically forced into historically horticultural land can be without strong geographically large states to force the transition to be made with money instead of violence can look. But with strong states that remove violence as a viable option, the transition, while still massively disruptive, could be less tragic in places like North America and Western Europe.
Similarly, the skiing industry might relocate from places like Colorado and Vermont to places like the Yukon and Alaska, in North American, and from places like the Alps in Europe to the northern Urals and the Himalayas in Eurasia.
Many Sunbelt communities in places like Arizona and Texas and Florida may see the waves of migration to avoid the cold winters of the north replaced by migration north to avoid the months of hundred degree plus water in the Sunbelt which are already commonplace in cities like Phoenix and Las Vegas, while the rust belt, with its winters made milder due to global warming and abundant fresh water, may start to look more attractive, and may attract mass return migrations.
One of these days, people in the Sunbelt may return to the traditional solution of having midday siestas, inside cooler, shaded adobe insulated homes, and becoming more active once the sun goes down and the air cools late into the evening.
Coastal communities will have to build dikes or lose land area as sea levels rise, and many will have to remake their architectural landscape in the face of increasingly severe storms, something that will hit the U.S. states of Florida and Louisiana and some islands in Oceania particularly hard.
Species limited to narrow microenvironment ranges will go extinct en masse, as human encroachment upon their habitats, ecological disruption, and human predation have already done to many species already.
How fast will it happen?
We are, in 2026, at about the place on this path that we thought we'd be in the year 2006, back in 1986. Events like the transitions to EVs and heat pumps and renewables and industrial scale organic farming happened, but it took about twice as long as futurists at the time thought that it would.
Climate change, on the other hand, is happening faster than expected by a decade or three. The changes that were initially looking like they would take a century to run their course are now looking like they will occur in half of that time.
Certainly, these transitions are medium to long run trends. They will probably takes decades more to run their course. These transitions probably won't be complete in my lifetime, although they probably will run their course in the lives of my children, or at least, in the lives of my future grandchildren.
But these trends are both massive and inexorable, like plate tectonics but much, much faster. Fast enough that it will be visible in future tree ring records.
Conclusion
These are huge, traumatic changes that will force mass migrations and fundamental changes in people's day to day culture. But they don't mean the end of modern life as we know it either. And falling birthrates will eventually lead to smaller global and regional populations that put less strain on scarce water and fossil fuel resources.