Emissions per capita

 This chart from Our World in Data shows emissions per capita (average for the world) by sector.

This is an average for the world, but, obviously, it is the wealthy and wealthy countries which emit the most. 

By far the largest is electricity and heat at 2,100 kg per capita.  It's also essential that electricity is decarbonised to reduce emissions in other sectors.  So this is the most important sector where we need to cut emissions.  The problem is, it's challenging to do it without the community being behind it.  We buy our electricity from the grid.  If the grid is mostly fossil fuelled, then how do we reduce our personal emissions from this sector?  

In countries where rooftop solar is cheap, this is an obvious way.  But, of course, you have to have your own rooftop.  And many live in flats, or rent their houses.  You can buy plug-in solar — a single solar panel with an inbuilt transformer, which can be plugged into your home grid without required expensive electrical work by an electrician.  But this is only just taking off, and legacy electrical utilities are hostile because it reduces their sales and profits.  

You can replace your oil/gas heating with a heat pump.  But heat pumps are costly up front.

Or you can, with others, set up your own co-op, build your own wind/solar farm, and connect it to the grid.  But then you come up against legacy vested interests who bitterly oppose these initiatives.  In some countries, you can buy your electricity from a green supplier — just don't choose one which uses offsets to convert black electricity to fake green.  Offsets are almost always a scam.

Since it's so hard to reduce your emissions from electricity without the political will from politicians and political parties (vote!  vote!  vote!), reducing emissions from other sectors becomes even more important.

The next largest sector for emissions is transport, which includes cars, light trucks, heavy-duty trucks, buses, and trains.  Outside the USA, EVs have fallen so much in price that they cost up front about the same as petrol/diesel cars, and they are much cheaper to run.  If cars make up 75% of emissions from this sector, you could cut your emissions by 750 kg/year if you switched to an EV.  (But, remember, if you are from a rich country, your cut will be proportionately much larger.)

The next big source is agriculture.  The numbers here vary a lot, partly because measurement is tricky, partly because of accounting for methane (which is usually included as 20 times as potent a greenhouse gas as CO2 over 100 years, but should prolly be counted as 80 times as potent over 20 years), and partly because some figures include land use change (deforestation, mostly for beef).   By going vegetarian, you could cut your personal emissions from agriculture by 75%, another 580 kg/year.

There is little you can do about manufacturing and construction.  This is mostly cement, steel and chemicals.  You need government, i.e., collective, action here.  Regulations and taxes need to be changed to force de-carbonisation.

There's no getting away from it.  Yes, you can personally cut your emissions, and you should, but most emissions come from sectors over which you have no control, and reductions there require collective, i.e., political action.  A carbon tax, also applied to imports from countries which don't themselves have a carbon tax, should be our most pressing objective.  If the cost of emitting rises, you can be sure that producers will work hard to reduce their emissions, and consumers will switch away from high-carbon products because they will cost more.  A comprehensive carbon tax is by far the best way to cut emissions, since it will tweak the price system to discourage carbon-intensive production and demand.  But it is also unpopular, even among people who cars about climate change.  We need to change that.