This poster created by nasa shows the effect of climate change on them or glacier in alaska this picture shows that between 1941 2004 the glacier retreated several miles and became much thinner which questions would clarify this evidence

It is useful for historians to write narratives so that history can be passed on from their point of view.  think about a story being told in third person, then think about it again being told in first person, by someone who actually experienced the event.

B  maybe the answer hoped it  

When a lake, river or other aquatic  system  becomes  eutrophic, it can have serious negative effects on other organisms like fish, birds and even people.if an algal bloom is so bad that it causes wide-spread death  in  the  water, the organisms that die will all sink to the bottom and start to decompose.

We can not answer this question because we cannot see the graph,sorry< 3