Barbara W. Leyden (18 December 1949 – 4 February 2006) was an American palynologist and paleoecologist.
The United States of America (USA), commonly known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, and various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is slightly smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U.S. is the third most populous country. The capital is Washington, D.C., and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico. The State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean. The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The extremely diverse geography, climate, and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleoecology is the study of interactions between organisms and/or interactions between organisms and their environments across geologic timescales. As a discipline, paleoecology interacts with, depends on and informs a variety of fields including paleontology, ecology, climatology and biology.
Leyden earned her Ph.D. from Indiana University in 1982. She conducted her research and taught at University of South Florida and frequently wrote about climate change in the late Pleistocene era in the western hemisphere.
Indiana University (IU) is a multi-campus public university system in the state of Indiana, United States. Indiana University has a combined student body of more than 110,000 students, which includes approximately 46,000 students enrolled at the Indiana University Bloomington campus.
The University of South Florida, also known as USF, is an American metropolitan public research university in Tampa, Florida, United States. USF is also a member institution of the State University System of Florida. Founded in 1956, USF is the fourth-largest public university in the state of Florida, with an enrollment of 50,755 as of the 2018–2019 academic year. The USF system has three institutions: USF Tampa, USF St. Petersburg and USF Sarasota-Manatee. Each institution is separately accredited by the Commission on Colleges of the Southern Association of Colleges and Schools. The university is home to 14 colleges, offering more than 80 undergraduate majors and more than 130 graduate, specialist, and doctoral-level degree programs.
Climate change occurs when changes in Earth's climate system result in new weather patterns that last for at least a few decades, and maybe for millions of years. The climate system is comprised of five interacting parts, the atmosphere (air), hydrosphere (water), cryosphere, biosphere, and lithosphere. The climate system receives nearly all of its energy from the sun, with a relatively tiny amount from earth's interior. The climate system also gives off energy to outer space. The balance of incoming and outgoing energy, and the passage of the energy through the climate system, determines Earth's energy budget. When the incoming energy is greater than the outgoing energy, earth's energy budget is positive and the climate system is warming. If more energy goes out, the energy budget is negative and earth experiences cooling.
