请教杨鹏难句中的107

louisehu

The correlation of carbon dioxide with temperature, of course, does not establish whether changes in
atmospheric composition caused the warming and cooling trends or were caused by their。

杨鹏的解释：，本句的省略很容易使读者将指代关系搞混：在最后的or were caused by their 当中，存在两处省略：or 之后省略了与whether 一句中相同的主语changes (in atmospheric composition)；最后的their 之后又省略了与whether 从句中的主语一样的changes。这里不管将their 之后被省略的内容看成是warming and cooling trends 还是看成composition 都是错误理解。

按照杨鹏的解释，or 后面补全就变成 changes were caused by their changes。 这怎么理解啊？
我怎么觉得应该是省略了 the warming and cooling trends?
求高人指点？

louisehu

Thanks！