By Hugh Brady
Review of Field Trial Results for Pointers and Setters in 2021
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efore my Report on Pointer & Setter Trials I’d like to share some thoughts on global warming and conservation: Many of the readers of this magazine are conservationists and environmentalists as their sport and one of their primary enjoyments relies on habitats with flourishing flora and fauna. We have all become familiar with the many international initiatives to reduce the emission of carbon dioxide to combat global warming. But what does it all mean and what is the context for Ireland as a country? The Earth is estimated to be 4.54 billion years old, plus or minus about 50 million years. This extraordinary estimate is based on scientists that have searched the Earth for the oldest rocks to radiometrically date. Rocks in north western Canada, are estimated at 4.03 billion years old. Scientists say that our ancestors have been around for about six million years but the modern form of humans only evolved about 200,000 years ago. Modern civilisation as we know it is only about 6,000 years old, and industrialisation started in the earnest only in the 1800s. Scientists have documented five mass extinctions. Most of the extinctions, as today, are a trade-off between oxygen and carbon dioxide and its impact on global warming or cooling. The first documented was the Ordovician Mass Extinction (440 million years ago). This mass extinction event is thought to be caused by the shift in the continents and the consequent drastic climate change. It happened in two different waves. The first wave was an ice age that
encompassed the entire Earth. As the climate went to freezing, sea levels lowered and many land species could not adapt fast enough to survive the harsh, cold climates. The second wave was when the ice age ended and the thaw began. This episode ended so suddenly that the ocean levels rose too quickly to hold enough oxygen to maintain the species that had survived the first wave. Species too slow to adapt were wiped out. The Devonian Mass Extinction (375 million years ago) occurred just as the climate stabilised and species adapted to new environments and life on Earth began to flourish again. In this Extinction almost 80% of all living species in the water and on land were wiped out. There are several explanations as to the cause of this second mass extinction. The first wave, which dealt a major blow to aquatic life, may have actually been caused by the quick colonisation of land where many aquatic plants adapted to live on land, leaving fewer autotrophs to create oxygen for all of the sea life. This led to mass death in the oceans. The plants' quick move to land also had a major effect on the carbon dioxide available in the atmosphere. Scientists estimate by removing so much of the greenhouse gas so quickly by afforestation, temperatures plummeted. The Permian Mass Extinction (250 million years ago) is the largest of all known mass extinctions with a massive 96% of all species on Earth completely lost. This major mass extinction has been called “The Great Dying.” Aquatic and terrestrial life forms alike perished relatively quickly as the event took
place. This could have been caused by massive volcanic activity paired with asteroid impacts that sent deadly methane and basalt into the air and across the surface of the Earth. These could have caused a decrease in oxygen that suffocated life and brought about a quick change in the climate. The Triassic-Jurassic Mass Extinction (200 million years ago) happened over a long time span, about half of all known species on Earth at the time perished. The causes of these individual small extinctions can, for the most part, be attributed to volcanic activity with basalt flooding. The gases spewed into the atmosphere from the volcanoes also created climate change issues that changed sea levels and possibly even pH levels in the oceans.
The event that wiped out the dinosaurs The final Mass Extinction so named Cretaceous-Tertiary (or the K-T) is the event that wiped out the dinosaurs. The dinosaurs were not the only species to go extinct, with up to 75% of all known living species dying during this mass extinction event. It is documented that the cause of this mass extinction was a major asteroid impact. The huge space rocks hit Earth and sent debris into the air, effectively producing an “impact winter” that drastically changed the climate across the entire planet. Scientists have studied these large craters left by the asteroids. After a large mass extinction event, there is typically a rapid period of specialisation among the few species that do survive; since so many species die off during these catastrophic events,
Irish Country Sports and Country Life Spring 2022
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