Abstract
The relationships between inter-annual variation of the growth of terrestrial vegetation, climatic variation and atmospheric CO2 content were examined. The variation of vegetation activity expressed by NDVI variation was well correlated with that of air temperature and precipitation, although the relation to the air temperature and precipitation was different in the region. Air temperature-dominated region was distributed mainly in Northern Hemisphere, and rain-dominated region was widely recognized in the Southern Hemisphere. The time change of the NDVI anomaly was found to be very similar to that of annual mean atmospheric CO2 content, and plus NDVI anomaly was corresponding with plus atmospheric CO2 content anomaly. The annual amplitude of atmospheric CO2 at Point Barrow, Alaska, well synchronized to the anomaly of NDVI. In the warmest year in 1990, atmospheric CO2 on June and July, beginning of growing season, decreased compared with that of previous year. This suggests the existence of the causality or interaction between plant growth, atmospheric CO2 and climatic variations, however, there exists two relationships in inter-annual and seasonal scales. The one is global increases in atmospheric CO2 and NDVI, and the other is local absorption of CO2 in growing season by enhanced vegetation growth due to worm weather.
