Complex sentence: The natural science bias in the IPCC has lead to a stronger involvement of juridical and economic aspects and as well, e.g. in the Stern Review, to attempts outside the IPCC to urge politicians to act on climate based on economic deliberations.
Split into simpler sentences: The natural science bias in the IPCC has lead to a increasing involvement of juridical and economic aspects. As well, e.g. in the Stern Review, there were attempts outside the IPCC to urge politicians to act on climate based on economic deliberations.