I do not feel the excitement/environment paradox when it comes to motorsports. COMBINED, all the local kart tracks*, dirt ovals, drag strips, race circuits, street circuits, hillclimbs, desert rallys, rally raids, endurance races, and their support infrastructure plus even sim racing in our living rooms and hobby caves contribute far less to than the actual forms of fossil fuel power upon which our modern lives rely: heat and electricity generation coupled with bus, auto, train, water, and air travel and transport.
Racing and related hot rodding / auto restoration hobbists are the ORIGINAL recyclers taking tired cars and powertrains and repurposing them in clever ways. Look at all the vintage Detroit iron which resourceful Cubans have managed to keep on the road despite nearly six decades of U.S. embargo.
I do, however, feel the twinge you feel about environmental impact when pursuing my largemouth bass fishing hobby which--at the top tiers--sees 200+ HP outboard motors exhaust spent hydrocarbons DIRECTLY into the water through their propellers. As much as I Iove the roar of a Mercury powerhead at full song, I would like to see more application of EV and fuel cell technology to recreational watersports. Sadly this is probably 50 years distant for even minimal adoption.
When one considers at the horsedrawn world that the internal combustion engine era supplanted, we no longer have the filth and disease of thousands of horses and their excrement and even dead carcasses. Which brings me to horse racing--you would be appalled at the numbers of these beautiful animals are literally ground up for the sake of sport. For every Seabiscuit there are 1000s of thoroghbreds sacrificed on the altar of greed and ambition not to mention harness racing breeds.
*Most environmental activists seem blind (and deaf) to the horrible noise and air pollution produced by gas powered lawn and garden equipment, most of which use ancient and dirty two-cycle ICE tech. I have a cordless electric mower which I value for its quiet operation and lack of poisonous exhaust. It carries the added plus of not needing to and transport gasoline cans inside the passenger compartment of my car. And that's when you can find pure gasoline which does not contain ethanol* which damages fuel system components.
Which leads me to the totally obsession of monoculture yards of bluegrass especially in the U.S. . . . What a massively obscene waste of precious water, human time, fertilzer and chemicals, and financial resources! Beautiful, biodiverse, and locally suited vegetation can be cultivated so much more easily and with more benefit to the eye and to dwindling pollinator populations.
You can see from my diatribe above that the issue of human activity upon the climate is one that should be not just with visceral knee jerk action to ban one group's livelihoods or hobbies**, but with a wholistic approach.
*As a midwesterner, I understand the monetary value of ethanol to farmers in this region, but ethanol production is a subsidized shell game which does not add up on paper. It takes diesel and fertilzer and chemicals--all derived from petroleum plus-to produce corn which would be moral use feeding humans. Add in the heat from natural gas to distill the fuel and there's another sketchy equation.
**Environment Canada effectively scuttled all professional drag racing in that country with a lead fuels** ban. With the stroke of a pen, the nitro methane-burning top fuel dragsters and funny cars which are the kings of the sport were outlawed. That pen cost Canadians millions in revenue from the spectators to the Sanair racing faxility for the NHRA LeGrand National. Compared to gross emitters such as electeical generation, rail, and shipping, the environmental impact of one national event a year would have been negligible.
***General aviation suffered for a time in the U.S. as older planes relied on the higher octane and compression cushioning of tetraethyl lead. I am not privy to the details of that changeover, but I am sure it would have had for A&P mechanics adding hardened valve seats to cylinder heads (or cynically, chemical manufacturers of lead additives which prolong the continued aerial emission of lead!)