Deadly heat waves, home-wrecking hurricanes, neighborhood-burning wildfires...When you stop to think about it, global warming can be thoroughly depressing. According to rising evidence, climate changewon't just cause new cases of stress, anxiety and depression. People who already have serious psychological problems will probably suffer most in the result of natural disasters and extreme weather events. "When these events happen, people with pre-established mental illnesses often have more extreme difficulty," said Lisa Page, a psychiatrist. "This is an area we maybe need to think about a little more seriously."  In public health circles and even in climate talks, scientists have studied how climate change might affect physical health, by for example, causing the spread of malaria, fever and other infectious diseases.  For the most part, though, the experts have made only vague references to the link between climate change and mental health, even though evidence for such connections is starting to pile up. In the future, climate models predict more destructive storms, floods, droughts and diseases. In turn, the new study suggests, more psychological crises will follow.  Heat waves -- like the one that killed some 70,000 people in Europe in the summer of 2003 -- will also happen more frequently, last longer and be severer in coming years. The mentally ill will be hardest hit by these events because they're more likely to live in poor housing without air conditioning.  People with pre-existing mental challenges will probably also have an extra hard time dealing with other forecasted consequences of climate change, including the sinking of coastlines and mass migration away from flooded shores. Then, there's the general sense of sadness that can come from reading about climate change, and recognizing that the world is changing. According to the text, people feel sadder when  _  .
they go for a walk in a sunny day. they think of global warming they move away from flooded areas they go outside to the coastlines