1. The results are charts that are,at least compared with the climate graphics presented by the IPCC,surprisingly simple,and that help reveal the troubling direction the world is headed.
head：朝...前进，做不及物动词，怎样理解这里的headed呢？
【答】the world is headed  是定语从句，先行词是direction，省略了in which，即：

and that help reveal the troubling direction in which the world is headed.

be headed in the dirction（朝着这样的方向前进）。类似 the way 后面的定语从句，省略in which 一样。如：Do it the way (in which) I did it.
head 用作动词可以及物，可以不及物，意思相同：
（1）head for/to + 地点
（2）be headed for/to + 地点 （被动式无被动意义，如果没有地点，则去掉for/to。本句是 be headed in the direction）

2. It also calls for remaining fossil fuels,such as coal and oil, to remain in the ground,never to be burned to generate energy,a key goal for many climate activists.
这里的两个to do不定式可以理解为状语，逻辑主语为coal and oil吗？
【答】本句结构是：call for + 宾语 + to do...（宾补）。即：
calls for remaining fossil fuels  to remain in the ground
such as coal and oil：such as  常用来列举前面的事物，coal and oil 是 fossil fuels 其中的两种，为其定语。所以，to remain ...是不定式作宾补，fossil fuels 是其逻辑主语。