Paleocene-Eocene Thermal Maximum (PETM) for Global Warming

Paleocene-Eocene Thermal Maximum (PETM) for Global Warming Josh Chaplin â€Å"Can the Paleocene-Eocene Thermal Maximum (PETM) be used as an analogue for anthropogenically-induced global warming?† The Paleocene-Eocene Thermal Maximum (PETM) was a global climatic occurrence in the early Paleogene period, spanning across the Paleocene and Eocene epoch overlap at 55.8 Ma (Gradstein et al 2004). Although the exact start and end points of the PETM are disputed, drilling in the North Sea and the Southern Ocean’s Weddell Sea has allowed an accurate duration of the phenomenon to be calculated to around 170,000 years. There is, though, much controversy over these figures and the mechanisms that caused such a climatic anomaly, but particularities aside, this geologically recent warming cycle may be of much use when it comes to understanding our changing climate today. A proposed cause of the PETM thermal anomaly is the release of 1,500 Gt of methane and carbon from decomposing gas-hydrate reservoirs in the terrestrial biosphere, initiated as part of a sequence of events leading on from mass volcanism associated with the opening of the North Atlantic (Winguth 2011). The resulting rise in temperature of around average 5.6 °C, and up to 9 °C is comparable to extrapolations which predict the temperature shift by the end of the current century (Rà ¶hl 2000). Sluijs (2007) explains how the climatological evidence for this comes from Oxygen isotope excursions in foraminifera and terrestrial carbonates, increased levels of Magnesium and Calcium in foraminifera and the poleward migrations of tropical plankton, mammals and terrestrial plants. On the other hand, the inception of the modern warming period was human-induced, and carbon was released from traps much faster than it would have been during the PETM, and has thus accumulated in the atmosphere a t a higher concentration in a shorter space of time. The PETM did not surpass a so-called ‘tipping point’ whereby the effects of the warming would be irreversible, whereas the exteremely rapid release of carbon over the course of the past three centuries may have catalysed such a scenario. As a result, it is a reasonable assumption that it may be possible to rely on the PETM as an analogue for modern anthropogenic climate change, due to the analogous effects and root cause, however it must be remembered that the speed of the onset may very well render these expectations void. There are a number of close similarities between modern and past warming periods which vouch for the validity of using their analyses as an analogue for what is happening at present, and what will be still to come. For example, anthropogenically-induced warming and the natural warming of the PETM both were the consequence of excess carbon in the atmosphere. In addition, the scale of temperature rise during the PETM is consistent with predictions for the end of the current century, at around 6 °C (Rà ¶hl et al 2000). Applying the principle of uniformitarianism, the climatic reconstruction of the conditions throughout the PETM can be useful in aiding us to understand what is happening and the effects we can expect. As the globe warms up, consequences occur such as the thermal expansion of the oceans and the release of terrestrial carbon which also have knock-on corollaries as is seen today (Hayward 2011); this is shown in Figure 1. Furthermore, due to the geologically relative recen t occurrence of the event, it is more reliable to construct climatological models and replicate what the potential consequences of the warming may be. This is another advantage in using what we know of the PETM as an analogue for what is happening to the planet at present. Modern Global Warming is, however, remarkably different from the rise in temperature associated with the PETM. Whilst the rise of the temperature today is comparable to the Late Paleocene at around 6 °C (Rà ¶hl et al 2000), the onset of this thermal spike occurred naturally and at equilibrium climatic state. The industrial revolution and the resulting vast amounts of coal, oil and gas which have ended up in the atmosphere as CO2 since the early 1800s have bought about the temperature shift in a very small fraction of the time than it did during the Paleogene. Figure 2 puts this into perspective. The anthropological extraction of carbon reservoirs has depleted their stratigraphic storage much quicker than would be the case naturally through uplift and erosion. â€Å"PETM: Global warming, naturally† (2012) states around 5109 tons of Carbon was released into the atmosphere each year during the PETM, whereas the figure for 2010 alone is 35109 tons. Such rapid accumulation of ca rbon in the atmosphere has never been reconstructed within the last 20 million years, and current atmospheric concentrations of CO2 are higher than at any point within the last 800,000 years (Hayward 2011). With reference to Figure 1, the knock-on consequences of each occurrence within a warming cycle are numerous, and the simultaneous onset of several of these is largely uncharted territory. A tipping point could theoretically be reached whereby global temperatures spiral out of control because of this, and drawing from the reversal of snowball earth periods, such an extreme planetary climate could take many millions of years to return to optimal conditions, if ever again. When considering the centuries that are required to transport all heat to the deep ocean and the millennia needed to remove excess carbon from the atmosphere, the consequences of climate change will still be materialising for generations and will likely last for longer than the 170,000 years it took the earth to remove all excess CO2 from the atmosphere. By 2300 sea levels are expected to be up to 0.8m higher than 1980 levels, many more species will be extinct and the poles will have considerably smaller ice sheets if still in existence, and one can only assume the repercussions will be more severe than the altered migration patterns and dinoflagellate calcite levels of the PETM. In conclusion, the PETM can be considered as an analogous representation of the warming of the globe. In the case of anthropogenic climate change however, the rate of carbon accumulation simply means that the potential consequences of the climatic shift are too unpredictable in years to come. Using the PETM as an analogous model for the current period of warming may suffice for the present, but future outcomes are uncertain as atmospheric carbon continues to accrue at an alarming rate. References: Gradstein et al (2004) – â€Å"A geological timescale† Hayward, A. et al (2011) – â€Å"Are there Pre-Quaternary Analogues for a future Greenhouse Warming?† 933-941 â€Å"PETM: Global Warming, Naturally† (2012) – Found at http://www.wunderground.com/climate/PETM.asp?MR=1 Rà ¶hl, U. et al (2000) – Geology Issue 28 – â€Å"New chronology for the late Paleocene thermal maximum and its environmental implications† 927-930 Sluijs et al (2007) – â€Å"The Palaeocene–Eocene Thermal Maximum super greenhouse: biotic and geochemical signatures, age models and mechanisms of global change† 333-338 Winguth, A. (2011) – â€Å"The Paleocene-Eocene Thermal Maximum: Feedbacks between Climate Change and Biogeochemical Cycles† 43-45

Black People and Birdie Essay

In her novel Caucasia, Danzy Senna paints the image of a young bi-racial girl, Birdie, growing up in the 70’s and 80’s. Her mother is a white, blueblood Bostonian woman turned political activist, and her father is a black Boston University professor with radical ideas about race. Birdie and her older sister Cole are both bi-racial children, but Cole looks more black and Birdie looks more white. The two sisters are separated early in the novel and then the rest of the story focuses on Birdie and how she needs to â€Å"pass† as white. Passing is the ability of a person to be regarded as a member of social groups other than his or her own, such as a different race, ethnicity, social class, or gender, generally with the purpose of gaining social acceptance. Birdie’s existence is the ultimate experiment on how to pass. She is first asked to pass as black at Nkrumah, even though she doesn’t fit the profile of a black child. Then she is taken to New Hampshire and asked to be the opposite of what she’d been before- a white Jewish girl. Senna introduces Birdie to all different versions of the races she is torn between, and none of them seem to fit quite right. Through Birdie, Senna is making the point we see that there is no one size fits all version of any race. Birdie is exposed to many different ideas of what it means to be black while she’s younger, even though the general idea of the time was very specific. All of the adults around her are busy preaching this idea of The Black Person, but they are showing her all different versions of what that really means. The first impression she gets of a black person is her father who â€Å"in the past year had discovered Black Pride and†¦ was trying to purge himself of his ‘honkified past’†(10). Deck is an intellectual; he studied at Harvard and is a professor at Boston University. However by the time his daughters are old enough to really start understanding things, he has gotten caught up in the idea of The Black Person, saying things about his sister like â€Å"she sleeps with these white boys, then acts surprised when they don’t take her home for dinner. I told her, these ofays just want their thirty minutes of difference†(10). He’s telling his daughters that the way to truly be black is to have no association with white people, which is a direct contradiction of his own life and something that is impossible for them to do given their genealogy. He’s telling them there’s no way for them to be the ideological black person. Then the girls go to Nkrumah, a black power school. This school is supposed to be about owning your race and being proud of being black, but Birdie isn’t initially accepted well because she’s not ‘black enough’. The way she becomes more accepted is through her sister, but also because she assimilates to the idea of black culture that her school has. She reads Ebony magazine, speaks in a specific slang, dresses differently and does her hair in a braid to hide it’s smoothness. At Nkrumah, she tries to live as though she doesn’t have a white mother. However, that’s not who she is. She says that she â€Å"learned the art of changing at Nkrumah, a skill that would later become second nature†(62). She’s acknowledging here that this all black persona isn’t who she is. She’s simply changing, pretending. Pretending is what Birdie has to do for most of this book, but as she gets older instead of needing to pass as black, she needs to instead adopt a new identity as Jesse Goldman, a Jewish white girl. She maintains in her mind that she is black, and is just pretending with her white half. While using this persona, and having the mindset that she is just gathering information on whiteness, Birdie gets painted a picture of different types of white people. In an authoritative sense, Birdie gets ideas about being white from her mother and her mother’s boyfriend Jim. Jim is the type of white man who likes to act like he’s liberal until it comes down to real world circumstances. After causing a scene with some young black men, Jim says â€Å"I swear, I try to be liberal. I try really, really hard. But when you meet fucking punks like that, you start to wonder. I mean, Jesus, what did we do to deserve that? We’re on their side and they don’t even know it† (265). Jim is the white man who sees his liberality as a gift instead of a belief. Birdie says about this that â€Å"it scared me a little†¦. how easily they could become cowering white folks, nothing more, nothing less† (264). To contrast these this very negative views of what it means to be white, Birdie also has her mother as a model. Despite coming from an upper class, white family and the struggles that she has with that, Sandy is a white person who firmly believes in equality, even if she may take it to extremes. She tells her daughters â€Å"that politics weren’t complicated. They were simple. People, she said, deserved four basic things: food, love, shelter, and a good education† (22). This is the opposite from what Birdie has seen in other white people. Her mother doesn’t revert to racism or abandon her views when it comes time for her to uphold them. Finally, Birdie befriends the most racist girls in school saying it’s because â€Å"there was a safety in this pantomime. The less [she] behaved like [herself], the more [she] could believe that this was still a game†(233). However, as much as she’d like to say she’s acting, she assimilates to this culture just like she did the black culture at Nkrumah; â€Å"I was a New Hampshire girl now†¦we dressed identically: cutoff jean short, halter tops that exposed our tan bellies, and jelly shoes on our feet† (244-245). This version of being white was a skin Birdie could slide on easily, even if she didn’t really want to. The only thing that shocks her out of the comfort she’s fallen into in this identity is the fact that another half black girl recognizes that she’s not fully white; â€Å"I’m black, like you† (286). None of these ideas about race fit Birdie. She cannot exactly fit into a version of what it means to be white because that’s not the only part of who she is. She also cannot be fully black, not only because she has light skin but also because that’s not the only part of her heritage that exists. Birdie is the perfect example of how multidimensional race is. There is no one way to be black and there is no one way to be white. Race isn’t one size fits all.

The Effects Of Oil Prices On Economic Activity - 1525 Words

Recent decline in oil prices has generated a wave of public controversy about the possible consequences for oil exporters. This paper will examine the relationship between oil price dynamics and macroeconomic indicators in oil exporting countries such as Canada, Russia, Norway, Mexico and UK. The hypothesis of oil price effects will be tested by adopting the Vector Autoregression (VAR) framework, which has been widely used to examine the effects of changes in oil price on economic activity in other papers. The main findings of this paper conclude that there is a considerable relationship between oil prices and key macroeconomic indicators in the countries under analysis. The impact of oil prices varies among countries with the biggest and expanding effect in Russia where a direct impact of oil prices on GDP growth, exchange and interest rates is detected. A significant response of GDP on oil price shocks is also detected in Canada and Mexico. As for Norway and UK relationship between real GDP and oil prices is not so significant, however, oil price dynamics has a significant influence on other macroeconomic indicators. 1. Introduction After four years of relative stability, oil prices have fallen sharply in June 2014. Many people have been arguing about the possible sources of the recent decline, whether the low prices will persist, and most importantly the possible impact of oil shocks on commodity exporters. This paper attempts to examine the historicalShow MoreRelatedEffects Of Lower Oil Prices On Canada s Economic Activity1520 Words   |  7 PagesLiterature Review Effects of Lower Oil Prices on Canada’s Economic Activity Consumer Price Index Falling oil prices leads to a fall in the price of gasoline which is derived from oil. Subsequently, consumption of gasoline rises as Canadians benefit from lower oil prices. 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In addition, the Kingdom of Saudi Arabia was instrumental in the formation of the OPEC (Organization of the Petroleum Exporting Countries) group, which initially comprised Iraq, VenezuelaRead MoreThe Price Of Oil Prices1096 Words   |  5 PagesSince summer 2014, the price of oil in the global market has drastically fallen. As measure by the U.S dollar, oil price has declined by around 50 percent from last year. The declining oil price is widely deemed as the effects of the increasing oil supply and decreasing demand in the global market among other factors. Future pricing predictions indicate that the price of oil will hardly be restored the level it was in recent years. The focus of this paper is to descr ibe how the basic supply and demand

How Important Was the Role Played by Edwin Chadwick in...

How important was the role played by Edwin Chadwick in improving public health services in towns in the nineteenth century? (16 marks) Edwin Chadwick’s hard-work produced a mass of evidence supporting public health reforms. In 1842 his report that was published (â€Å"Report on the Sanitary Conditions of the Labouring Population†) influenced the government and persuaded people that reform was needed. His report’s recommendations were the basis for the 1848 Public Health Act. However, Chadwick did have a few limitations along the way. His report in 1842 did not lead to immediate reform. The Public Health Act came 6 years later in 1848 and this act did not force councils to reform public health. His personality antagonised people and did†¦show more content†¦The core of the project was completed by 1865 but because it was such a big project, it took another 10 years to complete. He made sure the system had a much higher capacity than was needed in the 1860s. Other than this, there were other factors that helped improve public health such as the role of the government. In 1867, working men in towns were given the right to vote and this meant the number of voters doubled which increased again in 1884 and this mean politics changed drastically. In the 1870s/1880s many new laws were passed which were designed to improve the lives of ordinary people such as the Public Health Act in 1875. Another factor which helped improve public health was chance. The timing of the 1848 Public Health Act was the result of the latest epidemic of cholera. As cholera spread across Europe in 1847 fear grew in Britain of many thousands of deaths to come. Therefore the government finally followed Chadwick’s recommendations and passed the Public Health Act in the hope that this would reduce the impact of cholera. However, the 1848 Act was not compulsory. Only 103 towns set up local Boards of Health. Many more did not, and the National Board of Health, set up to oversee reforms, was abolished after only six years in 1854. The Great Stink in 1858 occurred in the summer which was really hot and this resulted in the smell from the river growing worse. This added to the evidence that more