During the 1970s, inventor/environmentalist James Lovelock and evolutionary biologist Lynn Margulis proposed the Gaia Hypothesis. This theory posits that Earth is a single, self-regulating system where the atmosphere, hydrosphere, all life, and their inorganic surroundings work together to maintain the conditions for life on the planet. This theory was largely inspired by Lovelock’s work with NASA during the 1960s, where the skilled inventor designed instruments for modeling the climate of Mars and other planets in the Solar System.
According to this theory, planets like Earth would slowly grow warmer and their oceans more acidic without a biosphere that regulates temperature and ensures climate stability. While the theory was readily accepted among environmentalists and climatologists, many in the scientific community have remained skeptical since it was proposed. Until now, it has been impossible to test this theory because it involves forces that work on a planetary scale. But in a recent paper, a team of Spanish scientists proposed an experimental system incorporating synthetic biology that could test the theory on a small scale.
The orbit of Earth around the Sun is always changing. It doesn’t change significantly from year to year, but over time the gravitational tugs of the Moon and other planets cause Earth’s orbit to vary. This migration affects Earth’s climate. For example, the gradual shift of Earth’s orbit and the changing tilt of Earth’s axis leads to the Milankovitch climate cycles. So if you want to understand paleoclimate or the shift of Earth’s climate across geologic time, it helps to know what Earth’s orbit was in the distant past.
NASA’s Plankton, Aerosol, Climate, ocean Ecosystem (PACE) satellite successfully launched and reached on Thursday, February 10th. The mission took off from Space Launch Complex 40 at Cape Canaveral Space Force Station in Florida, at 1:33 am EST 10:33 pm (PST) atop a SpaceX Falcon 9 rocket. About five minutes after launch, NASA confirmed that ground stations on Earth had acquired a signal from the satellite and were receiving data on its operational status and capabilities post-launch. For the next three years, the mission will monitor Earth’s ocean and atmosphere and study the effects of climate change.
After analyzing the temperature data from 2023, NASA has concluded that it was the hottest year on record. This will surprise almost nobody. If you live in one of the regions stricken by drought, forest fires, or unusually powerful weather, you don’t need NASA to confirm that the planet is warming.
During the 1960s, the first robotic explorers began making flybys of Venus, including the Soviet Venera 1 and the Mariner 2 probes. These missions dispelled the popular myth that Venus was shrouded by dense rain clouds and had a tropical environment. Instead, these and subsequent missions revealed an extremely dense atmosphere predominantly composed of carbon dioxide. The few Venera landers that made it to the surface also confirmed that Venus is the hottest planet in the Solar System, with average temperatures of 464 °C (867 °F).
These findings drew attention to anthropogenic climate change and the possibility that something similar could happen on Earth. In a recent study, a team of astronomers from the University of Geneva (UNIGE) created the world’s first simulation of the entire greenhouse process that can turn a temperate planet suitable for Life into a hellish, hostile one. Their findings revealed that on Earth, a global average temperature rise of just a few tens of degrees (coupled with a slight rise in the Sun’s luminosity) would be sufficient to initiate this phenomenon and render our planet uninhabitable.
Yesterday, NASA’s Goddard Institute of Space Studies (GISS) announced that the summer of 2003 was the hottest on record. This year saw a massive heat wave that swept across much of the world and was felt in South America, Japan, Europe, and the U.S. This exacerbated deadly wildfires in Canada and Hawaii (predominantly on the island of Maui) and are likely to have contributed to severe rainfall in Italy, Greece, and Central Europe. This is the latest in a string of record-setting summers that are the direct result of anthropogenic climate change.
This summer has seen a violent outbreak of forest fires across Canada and North America. According to the Canadian Interagency Forest Fire Center (CIFFC), there were 911 active fires across the country on July 13th, nearly 600 of which were characterized as “out-of-control.” More than half of these active fires are taking place in the provinces of British Columbia, driven by a combination of unusual heat, dry lightning, and drought. The situation is becoming increasingly common thanks to rising global temperatures, diminished rainfall, changing weather patterns, and other related effects of Climate Change.
Monitoring forest fires and other meteorological phenomena is an important task for which Earth Observation missions like NASA’s Aqua satellite were created. On July 12th, with six weeks left in the Canadian fire season, Aqua captured images of some of the largest fires over British Columbia using its Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The image above shows some of the biggest “hot spots” in the province, which produced dense plumes of smoke blowing eastward through the Rocky Mountains and into Alberta and the Northwest Territories.
Human-driven climate change is a serious threat to humanity. While climatologists continue to improve our understanding of its impact and consequences, they also look at nature-driven climate change going back millions of years. Whereas for human climate change, we only have a case study of one planet, for natural climate change we have a case study of two planets. Like Earth, Mars has undergone significant climate change in the past. We know, for example, that young Mars was both warm and wet. Its climate changed over a billion years to become the cold and dry world we know today. Even more recently, there have been shifts in the Martian weather, as noted in a recent study in Nature.
Despite decades of warnings and international climate agreements, global carbon emissions are still rising. Carbon emissions seem like an unstoppable juggernaut as energy-hungry humans keep breeding and pursuing more affluent lifestyles. Reducing emissions won’t be enough to confront the climate crisis; we need additional solutions.
Geoengineering, also called climate engineering, could be the solution we seek. But is it financially feasible?
Earth experiences seasonal changes because of how its axis is tilted (23.43° relative to the Sun’s equator), causing one hemisphere to always be tilted towards the Sun (and the other away) for different parts of the year. However, because of gravitational interactions between the Earth, Sun, Moon, and other planets of the Solar System, Earth has experienced changes in its orientation (obliquity) over the course of eons. This has led to significant changes in Earth’s climate, particularly the recession and expansion of ice sheets due to significant variations in the distribution of sunlight and seasonal changes.
These warming and cooling periods are known as interglacial and glacial periods (“ice ages”). Another interesting change is how the glacial-interglacial cycle has become slower with time. While scientists have long suspected that astronomical forces are responsible, they have only recently been able to test this theory. In a recent study, a team of Japanese researchers reproduced the cycle of glacial periods during the early Pleistocene Epoch (1.6 to 1.2 million years ago) using an improved computer model that confirmed astronomical forces were responsible.