Examples of how scientific evidence achieved or failed to achieve political change

One issue on which new scientific evidence drastically changed nations' positions was the problem of acidification and eutrophication in Europe. When the issue first came to light in Sweden and a couple other countries, it was largely ignored by other nations. However, after LRTAP was established, nations were able to see what effects were occurring in their nation, and where the pollutants were coming from. Germany in particular became one of the leaders of the treaty following discovery of German forest death. Scientific evidence change nations' positions because they could see drastic effects and harmful (immediate) pollution levels right at home. It was unignorable.

One area in which new evidence has often failed to change nations' positions is that of Climate Change. Despite growing evidence (much of which is very controversial), many nations (the US in particular) are reluctant to lower emission or place restrictions on development. In this case, the reasons are usually scientific uncertainty (lack of enough clear evidence), fears of being outcompeted by another nation in production, and the fact that the consequences of not acting will not occur for many years, if they do in fact occur. In this case, the issue is not so clear cut for many: putting restrictions on a company's emissions (and thus raising costs) is difficult when China is not held to the same standards, and when there is no immediate and visible effect of inaction.