What is the Nature of Climate Change?”

Forecasting the Future with Climate Change

As the Earth’s climate changes, determining what patterns of life will be sustainable for humans is a crucial question. As the availability of water and food continues to decline, people around the globe are looking for ways to address this issue. One possibility is how long a tree lives before it loses its leaves. This concept of leaf longevity is not new, but it is one that scientists are beginning to look at more closely as an indicator for climate change. The amount of time a tree’s leaves stay on has a large impact on how much energy the tree gets from photosynthesis from the sun and how much carbon is locked into the tree. Unfortunately, a tree’s leaf loss is determined by many factors including the tree species, season, year, and age of the tree.
The idea of using the length of time a tree’s leaves stay on before they fall as an indicator for climate change grows out of a couple different trends scientists are seeing in forests. The first is that in general trees are already expected to live shorter lives as global temperatures rise. Trees have to balance energy gain from photosynthesis against energy lost in respiration and growth. As temperatures increase, trees are expected to live shorter lives and lose their leaves sooner. (There is also another key factor that is not as easy to predict: tree size plays a role in leaf longevity.)

when do leaves come back on trees
when do leaves come back on trees

The Scientific Truth About Global Warming and How it will Affect Us

This change in weather patterns is caused by increased amounts of carbon dioxide being emitted into the atmosphere. The Earth absorbs most of the sun’s heat and energy which causes it to warm. The Earth then re-emits some of that absorbed energy as heat, which acts like a blanket over the planet. This trapped heat is what scientists call global warming. Global warming has occurred naturally in the past and there is evidence of it happening in the temperature record from 1,000 years ago. However, global warming over the past 100 years has been caused by humans. A changing climate is the result of rising levels of heat-trapping gases in the atmosphere such as carbon dioxide, methane, and nitrous oxide. Atmospheric levels of these gases are increasing due to human activities.
As carbon dioxide levels were relatively low during the 1880s, global warming was more pronounced than it is now. The Earth’s surface has increased its temperature by just 1 degree Fahrenheit over the past 100 years. The 15 warmest years on record have all occurred since 1998, with the current year of 2010 being the warmest year ever recorded. The decade from 2000 to 2009 has been the warmest decade in history. Some scientists consider the current level of carbon dioxide in the atmosphere to be 41% higher than it was at this time two decades ago. The worst-case scenario would suggest a jump much higher than that, with carbon dioxide concentrations reaching 450 parts per million by 2100. Such a drastic increase would result in temperatures rising between 3 and 6 degrees Fahrenheit by 2100. A study published in the Proceedings of the National Academy of Sciences predicts that by 2050, a rise of 5 degrees Fahrenheit is likely to have taken place.

when do leaves come back on trees
when do leaves come back on trees