1. Introduction: BackgroundHigh Speed ​​2 (HS2) is a proposed high-speed train between London and the West Midlands. The project was started in January 2009 by a company set up by the government to consider building a high-speed railway in the UK. This train will be able to travel at up to 400 km/h by 2020. High-speed trains have been successfully introduced in countries such as Germany, France and Spain (hs2, 2011). Building the high-speed rail would reduce journey times from London to Birmingham to 49 minutes and from London to Manchester and Leeds to 80 minutes. According to the government, Britain's railways are struggling to cope with the huge increase in passenger numbers that Britain's railways have experienced in recent years (dft, 2011). High-speed railways need straight lines to maintain their speed. According to the government, there are no viable routes for high-speed rail between London and the West Midlands that do not cross the Chilterns at some point. However they say the train will make full use of tunnels across the Chilterns to minimize impacts (dft, 2011). However, as we will see in the next section, full use of the tunnels does not mean that it would not have environmental impacts in The Chilterns. There are several aspects to classify its environmental impact in The Chilterns: biodiversity and ecosystem, noise pollution, carbon emissions and structural landscape (wendoverhs2, 2011). Ministers must make a decision to proceed with this project, which is currently very controversial.2. DelineationThe objective of this assessment is to outline the nature of the proposed high-speed rail and its environmental impact on the C...... middle of document ......0111: About the Chilterns. Available: http://www.chilternssaonb.org/about-chilterns.html (Accessed: 28 November 2011).- The Chilterns, 20112: Chalk Streams. Available: http://www.chilternssaonb.org/about-chilterns/chalk-streams.html (Accessed: 28 November 2011).- The Chilterns, 20113: Environmental impact statement on the Chilterns AONB. Available: http://www.chilternssaonb.org/uploads/files/high_speed_2/statement-of-environmental-impact-on-the-chilterns-aonb.pdf- The Chiltern Society, 2011: Concerns Arising from the Geology and Hydrology of the terrain beneath high speed routes (HS2) across the Chilterns. Available: http://www.chilternsociety.org.uk/hs2/paper02.php (Accessed: 1 December 2011). - Wendoverhs2, 2011: High Speed ​​Rail Briefing Number 1. Available: http://www.wendoverhs2. org /documents/WHS2_environment_090111.pdf (Accessed: November 26 2011).