In Earthâs history before the Industrial Revolution, Earthâs climate changed due to natural causes not related to human activity. Most often, global climate has changed because of variations in sunlight. Tiny wobbles in Earthâs orbit altered when and where sunlight falls on Earthâs surface.e know this because scientists closely monitor the natural and human activities that influence climate with a fleet of satellites and surface instruments. Remote meteorological stations (left) and orbiting satellites (right) help scientists monitor the causes and effects of global warming.
The heart is a muscular organ about the size of a fist, located just behind and slightly left of the breastbone. The heart pumps blood through the network of arteries and veins called the cardiovascular system.The heart has four chambers:he heart is a muscular organ about the size of a fist, located just behind and slightly left of the breastbone. The heart pumps blood through the network of arteries and veins called the cardiovascular system. The heart has four chambers:
The heart is located in the center of the chest, behind the sternum. In this video, Rakesh Jain, MD, an interventional cardiologist at Chippenham & Johnston-Willis Hospitals, describes both the location and size of the average human heart.he heart lies underneath the sternum, or chest bone, and sits a little to the left. The heart is located between the lungs and lies in front of the backbone. It is about the size of a fist. (This answer provided for NATA by the University of Montana Athletic Training Education Program.).