You want the speed and thrills of a Porsche 911, but you also don’t want your grandkids to be living in a climate refugee colony somewhere in the Scottish highlands. You want to tear up those winding mountain passes in your brand new Boxster, but you also very much enjoy your annual sojourns to Napa wine country and would prefer it to not burn to the ground.

It’s a relatable feeling, as I suspect most of us these days are racked with some degree of climate guilt. Porsche knows this, so they’ve launched , a CO2 emissions offset project in partnership with , a Swiss-based carbon offset organization.

For those unfamiliar, carbon offset programs use money gathered from polluters—either through taxes, fines, or donations—to fund projects that reduce CO2 emissions elsewhere, such as paying a country to not chop down a forest or build a solar farm.

Using the web form, a Porsche owner can estimate the amount of CO2 he or she will emit in a given year and purchase the accompanying amount of carbon offsets. Porsche estimates that a 2019 Cayenne S logging 10,000 miles a year would require somewhere between $67 and $152 per year to offset, depending on which project one chooses to support.

As lovely as it is to believe a mere $100 per year or so can offset one’s driving emissions, I am sorry to report it is not quite that easy. In fact, carbon offsets are a lovely idea that don’t work quite that well in real life.

For example, a found that these programs largely fail to deliver on the benefits they promise:

In case after case, I found that carbon credits hadn’t offset the amount of pollution they were supposed to, or they had brought gains that were quickly reversed or that couldn’t be accurately measured to begin with. Ultimately, the polluters got a guilt-free pass to keep emitting CO₂, but the forest preservation that was supposed to balance the ledger either never came or didn’t last.

In fact, researchers who have studied offset programs for decades told ProPublica that such programs may be doing more harm than good, because any reduction in CO2 they accomplish is, well, offset by the fact that people like us are told by massive companies like Porsche our additional CO2 emissions will be accounted for when in fact they are not.

So, by all means, go ahead and give South Pole $100 or so a year if you’d like. It will almost certainly not do any harm, so long as you understand it is not a free pass to emit as much CO2 as you like. The only thing you’re offsetting is your own lingering guilt.

Instead, I humbly suggest that the better way to enjoy your leisure drives without climate guilt is to use less energy in other ways. Maybe don’t turn on that A/C as often (or even just bump the temperature up a few degrees), or replace one commute a week with a more environmentally-friendly form of transportation. Save your money with your own personal carbon offset program.