Controversies in Science/Are humans causing global warming/A Critique of Global-scale temperature patterns and climate forcing over the past six centuries

(Review Paper) Cited in

Tree Ring Data Says Humans are Causing Global Warming
By measuring tree rings we can estimate temperatures for the past 600 years and show that human pollution is causing the world's temperature to rise.

Methods
Data was collected from several sources all around the world and compared. All the data gathered provide evidence of climate change, which greatly increased as human generations and CO2 output increases.

There are three rules outlined in this article. The first is that all trees that can tell temperature of times past. The second is that the trees don't need to be all from the same region, as they are all affected by the same atmosphere. The third rule is that time and trees are linear.

Northern Hemisphere and Arctic temperatures were studied and three species of "eleven tree-ring width chronologies" were used for that study.As a result, the times when temperature was at at higher mark, the tree rings were larger.

Results
There is global warming after the 20th century.

Due to studies done in the northern latitudes of North America, it has been proved that temperature is the dominant reason as to why tree grown is limited, especially in areas of high latitude.