Richmond Park = Full of tossers

The difference is you can't see the litter that most cars leave behind.

If 5000 cars drive an average of 3 miles through the park every day that's 6.45 tonnes of CO2 they leave behind.

Then you've got the NOx, the CO, the SO2 and the particulate matter.

(Based on an average of 430g CO2 per mile.)