__________ is the science of facilitating the return of a degraded ecosystem to a more natural condition.

Most scientific experts agree that climate change is already occurring and has potentially catastrophic consequences for all of life on Earth. The Paris Agreement of 2015 represented a global consensus on the need to reduce greenhouse gas emissions. However, in 2017 the United States announced its intention to withdraw from the Agreement in 2020. Go online to research and summarize the main agreements reached in this historic global climate accord and the U.S. government's reasons for withdrawing. What roles do you think scientists, politicians, and citizens will need to play to cut emissions and limit global warming?

SCIENTIFIC THINKING In 1954, workers at Michigan State University began spraying the elm trees on campus annually with DDT to kill disease-carrying bark beetles. In the spring of 1955, large numbers of dead robins were found on the campus. Observers thought perhaps the robins died after eating earthworms contaminated by DDT the previous spring. Suggest how scientists could have investigated the scientific validity of this idea.

What is a major advantage of herbicide-resistant crops?

The use of organisms to add essential materials to degraded systems defines __________.

One characteristic that distinguishes a population in an extinction vortex from most other populations is thata. it is a rare, top-level predator.b, its effective population size is lower than its total population size.c. its genetic diversity is very low.d. it is not well adapted to edge conditions.

Complete the following map, which organizes some of the key concepts of conservation biology.

What does species richness refer to? Select True or False for each statement.T/Fthe number of species in an areaT/Fthe evenness of species in an areaT/Fthe functional diversity of a species in an areaT/Fthe phylogenetic diversity of species in an area

Carbon dioxide functions as a greenhouse gas by .a. interfering with water's ability to absorb heat;b. increasing the random molecular motions of oxygen;c. allowing radiation from the sun to reach Earth and absorbing the re-radiated heat;d. splitting into carbon and oxygen and increasing the rate of cellular respiration