现在我们能够发现,各国的差异性是基于比较优势的贸易模式存在的基础.然而,在各国存在差异性的世界环境中,污染引致的非凸性与传统的贸易决定因素会产生相互作用.

不知是否说明白了.见谅!

你翻译的好像不对：Thus far we have abstracted from differences across countries that could create a comparative advantage basis for trade

我们已经提出了决定贸易的比较优势基础的那些国家差异。

谢谢各位了！！！！！！好人多……[em01][em01]

Thus far we have abstracted from differences across countries that could create a comparative advantage basis for trade.Pollution-created nonconvexities will however interact with the more conventional determinants of  trade in any world with nonidentical countries
至今为止我们已经知道，各国要素禀赋等的差异性是贸易相对优势存在的基础。正是这样的差异性，使得环境污染的非凸性与传统的贸易决定因素产生相互作用。

呵呵，翻译得可以吗，请指正。