The solutions? Build mass transit, live in temperate climates, buy less stuff, ...? Honestly, I don't think we're not going to fix the problem with simple, local improvements (though by all means do what you can). There are global demographic forces to contend with. A century ago there were 2 billion people on earth. Now there are >8 billion, and in my lifetime we will surpass 9 billion. Many of those people are climbing out of poverty, and they want cars and air conditioners and all the other energy-intensive things that rich countries have enjoyed for a century. IMO we're going to need massive technological changes (like powering much of the world with nuclear very soon) in concert with a major population reduction and/or major changes to how people expect to live.
Nuclear is: very slow to make, very expensive, generates dangerous waste, invites proliferation.
Wind and solar are quick, relatively much cheaper, create little waste. The sun is forever.
Personal transportation needs a complete redesign. Burning fossil fuel at 20% efficiency (80% waste) to push a 4000lb. vehicle with a 200lb person in it is insane. Personal electric vehicles of 200-300 lbs tracking defined lanes at 20mph under computer control would take care of 80-90% of urban travel needs. And greatly reduce the number of roads needed.
Side note: If worrying about climate isn't enough, we can also worry about potential famine as we use up our fossil fuels.
We are able to feed the world because of the Haber-Bosch process. This process uses fossil fuels, usually natural gas, to produce synthetic ammonia for fertilizer. That fertilizer makes modern high-yield farming possible. "Without the Haber-Bosch process we would only be able to produce around two-thirds the amount of food we do today." https://www.thechemicalengineer.com/features/cewctw-fritz-haber-and-carl-bosch-feed-the-world/
If you own your home, you can drastically reduce your carbon.
installing solar to take energy off the grid
install a heat pump to generate heat and cool off of electricity
even if your grid is pure coal, this is still more efficient than burning your own gas
you can keep a gas furnace as a backup, look up "dual-fuel" systems
take transit whenever possible
if you are in a car dependent area, look into e-bikes and EVs. Even replacing just your commuter car can have huge impacts, you don't have to replace them all.
While I agree with the idea of going vegan for the environment, it is unfortunately an unattainable diet for many people on the planet. It is not cheap to be vegan, even though with the wealth of technology and advancement we have it should be.
individual solutions reviewed and assessed by Project Drawdown, including their relevant sector(s) and their impact on reducing heat-trapping gases -> https://drawdown.org/solutions/table-of-solutions
Both the links above are from a very interesting video on the topic that I suggest to take a look at. Also the whole channel is really interesting and well done -> https://www.youtube.com/watch?v=ReXaS4QausQ
The excess production of useless shit that nobody would need or want without the manipulation of advertising convincing us otherwise. Cell phones and such are nice, don't get me wrong, but do we need thousands of factories around the world churning out cargo ships full of cheap plastic junk that's designed to fail? No. It only exists because it makes some rich people even richer, and it's burning our planet down. If all that productive capacity was bent to the purpose of meeting peoples' actual needs/reasonable wants it would be a different matter.
Excessive HVAC use: heating/cooling unnecessarily large spaces (as opposed to zoned) and by more degrees than necessary
Unnecessary and inefficient transportation. This includes most air travel, cruise ships, shitty urban planning, commutes for jobs that can be done remotely, large/inefficient automobiles.
Cryptocurrencies and AI
Consumer junk based on planned obsolence, lack of reliability, poor quality, and excessive packaging (often plastic)
Food - increased per capita consumption of animal products and egregious amounts of food waste.
Energy demand to power heavy industry that we all use (steel, aluminum, chemicals, fertilizers)
I don’t see these going away, so it’d be best to make their processes greener by repurposing the carbon into ag products, then institute a viable carbon tax and offset the rest of their footprint
Use of concrete in construction
some promising technologies coming that crystallize the carbon and use it to self heal the concrete, carbon tax and offset the rest
Shipping
bring manufacturing closer to consumers, global environmental manufacturing and shipping standards, improve right to repair laws
Transportation
upgrade public transportation options where it makes economic sense to do so, make our cities and towns more people friendly instead of car friendly, raise the gas tax to fund these efforts. Reduce the amount of detached single family housing stock and encourage multi-family stock, particularly in cities.
Heating and cooling
incentivize heat pumps, add taxes to heating fuels and fossil energy plants to fund it. Start a major campaign to educate people to keep temperatures around 68 (winter) to 76 degrees (summer). And encourage use of ceiling fans.
I don't think any industry pollutes more per client served than the cruise ship industry.
The most impactful things you can do for the environment is to push your representatives to pass regulations. The USA is absurdly unregulated at the federal level.
Most beneficial thing is to choose a more minimalist lifestyle. Buy only if you need it, use only if you must and discard only if you absolutely have to. These principles can be applied to pretty much everything, from eating at a restaurant to buying clothes to using technology.
There are numbers for these, you know. Biggest sources of carbon emissions are (1) burning fossil fuels and (2) land use change (converting natural ecosystems such as forests, grasslands and wetlands - to plantations, farmlands and concrete).