'Treescapes after the Ice Age': We will see how Britain was transformed once the ice sheets had disappeared approximately 16000 years ago. As the climate warmed trees moved north from Southern Europe but each species moved at a different pace so the landscape continually changed. The meaning of the terms 'native tree', 'naturalised tree' and 'introduced tree' will be discussed. We will also see the impact that mankind has had on our treescapes as we move towards modern times. (on-site or online)
'Remarkable Trees of Yorkshire': This talk will be jointly given by Alan Hunton and John Killingbeck. We will provide an illustrated tour of North and East Yorkshire stopping from time to time to view some of the county's more unusual trees. Some are remarkable by being large or tall or ancient whereas others are remarkable in a historical context or are uncommon. We will attempt to provide some interesting facts about each species described. (on-site only)
'Snowball Earth - the Story of the Earth's Ice Ages': The Earth is 4.6 billion years old and has been completely ice free for most of that time. 2.4 billion years ago an unusual sequence of events led to a sudden cooling and ice sheets spread towards the equator from both poles. The Earth became a snowball for 200 million years. These events have repeated at least twice more and in the most recent two million years we have entered another cycle in which ice advances and recedes. We will try to offer reasons for these events and we will predict the next ice advance -assuming mankind can control global warming. (on-site or online).
'History of Crude Oil - from Mesopotamian Origins to Colonel Drake': The discovery of crude oil and bitumen can be traced back to the Neanderthals but more widespread use started in Mesopotamia around 8000 BP. Ziggurats were made secure by oil bitumen mortar and Nebuchadnezzar allegedly waterproofed his hanging gardens with bitumen. Unlikely medicinal uses were found and it was not long before the flammable properties of crude were exploited the Byzantines who made oil grenades as a naval warfare weapon. We will see that in North America the native Indians were using crude oil as an insecticide and for skin treatments long before the famous sinking of Drake's Well in Pennsylvania in 1861. (on-site or online)
