What effect do coastal city have on the environment

Human activities in coastal areas have affected many of the natural environmental processes there. This has led to a wide range of issues including a loss of biodiversity, high levels of pollution, erosion, and rising sea levels due to climate change. In fact, coasts are one of the Earth's most threatened environments.

Cultural convergence is the theory that two cultures will be more and more like each other a very notable example of this is around the u.s.-mexico border, where 

Humid continental climate is found in the interior of continents between the 30 and 60 degrees latitude, but usually above the 40 degree line.   40 degrees north of the equator means less direct sunlight and therefore less warmth.   this climate is mainly found in the northern hemisphere since there are no major landmasses in the southern hemisphere.  if you live in northern indiana, you know all about humid continental because that is the climate type you have!