The impact on the extreme and frequency distribution of maximum temperature and convective precipitation resulting from a change in land cover is compared to the impact of an increase in CO2. Simulations using estimates of natural and current land cover at 280, 355, 430 and 505 ppmv were performed to explore the relationship between land cover change and CO2 level. We analyzed the return values of the annual daily maximum temperature and the seasonal changes of frequency in daily maximum temperature and convective precipitation over Europe and China. Our results confirm that increasing CO2 leads to increases in maximum temperatures and changes in rainfall intensity. We show that land cover change can cause similar impacts. Depending on the nature of the land cover changes, rainfall intensity and maximum temperatures can changed by amounts similar to those caused by increased CO2. In effect, the distribution of land cover can affect the climate's sensitivity to increasing CO2.