Another sign of Graves' disease is hyperthyroidism, i.e., overproduction of the thyroid hormones T3 and T4. Normal thyroid levels are also seen, and occasionally also hypothyroidism, which may assist in causing goitre (though it is not the cause of the Graves' disease).
Without this greenhouse effect, the average surface temperature would be 255 degrees kelvin (-18 degrees Celsius or 0 degrees Fahrenheit); a temperature so low that all water on Earth would freeze, the oceans would turn into ice and life, as we know it, would not exist.
Earth's Greenhouse Effect Energy from the Sun that makes its way to the Earthâs surface can have trouble finding its way back out to space. This is because of a natural process called the greenhouse effect. Without the greenhouse effect, Earthâs temperature would be below freezing. However, Earthâs greenhouse effect is getting stronger as we add more greenhouse gases to the atmosphere. And that is warming the climate of our planet. Heat is radiated into the atmosphere from the Earthâs surface, which is warmed by sunlight. As the heat makes its way back to space, much of it is absorbed by greenhouse gases in the atmosphere. Greenhouse gases are more complex than most other gas molecules in the atmosphere, with a structure that can absorb heat.