BBC Learnings · Section 7

Melting ice sheet Is it too late

With no end in sight to the coronavirus pandemic, many people can't wait for the year 2020 to end.

Level: C1 · 112 sentences

Transcript

  1. With no end in sight to the coronavirus pandemic,
  2. many people can't wait for the year 2020 to end.
  3. But with the coronavirus dominating the newspaper headlines,
  4. attention has moved away from an equally serious global issue,
  5. which has quietly been getting worse – climate change.
  6. August 2020 saw the hottest temperature recorded anywhere in modern times –
  7. 54.4 degrees Celsius in California's Death Valley.
  8. The same month also saw record amounts
  9. of ice melting into the oceans around Greenland
  10. and the Arctic – huge icebergs breaking away
  11. from the edge of the ice sheet –
  12. a thick layer of ice which has covered
  13. a large area for a long time.
  14. Greenland's ice sheet is three times the size
  15. of Texas and almost two kilometres thick.
  16. Locked inside is enough water to raise sea levels by six metres.
  17. But global heating and melting polar ice has many scientists
  18. asking whether it's now too late to stop.
  19. Have we reached the point of no return?
  20. In this programme, we'll be looking
  21. at the effects of climate change
  22. on the Arctic and asking if it's too late to change.
  23. And learning some of the related vocabulary too.
  24. Now, Georgina, you mentioned record levels
  25. of ice melt in the North Pole,
  26. but the scale is hard to take in.
  27. The amounts are so big they're measured
  28. in gigatons – that's a billion metric tonnes.
  29. Imagine a giant ice cube one kilometre
  30. by one kilometre by one kilometre.
  31. So, my quiz question is this – how many gigatons
  32. of ice are now melting into the ocean every year?
  33. Is it… a 450 gigatons, b 500 gigatons or c 550 gigatons?
  34. I'll take a guess at b 500 gigatons.
  35. OK, Georgina, we'll find out later.
  36. Now, glaciologist Michaela King has been monitoring
  37. the melting of Arctic ice by satellite.
  38. Here she is answering a question
  39. from BBC World Service programme Science in Action
  40. on whether the destruction of the ice sheet is now unavoidable.
  41. If we were to say define a tipping point
  42. as a shift from one stable dynamic state
  43. to another, this certainly meets that criteria
  44. because we are seeing now that the ice sheet
  45. was more or less in balance prior to 2000,
  46. where the amount of ice being drained
  47. from the glaciers was approximately equal to what we were gaining
  48. on the surface via snow every year.
  49. Ice is made from snow falling
  50. on Greenland's glaciers, large, slow-moving masses of ice.
  51. At the same time though, ice is also lost through melting.
  52. These two processes of making and melting ice
  53. kept the ice level in balance,
  54. having different parts or elements arranged in the correct proportions.
  55. Essentially, the melting ice was replaced by newly frozen ice.
  56. But now the glaciers are shrinking faster,
  57. the new ice is being accumulated
  58. and the situation may have reached a tipping point –
  59. the time at which a change
  60. or an effect cannot be stopped.
  61. So, does this mean that global heating
  62. and ice melting are now running automatically,
  63. separate from the amount of greenhouse gases
  64. humans are pumping into the atmosphere?
  65. And does that mean we should just give up on the planet?
  66. In fact, the situation is far from simple,
  67. as Michaela King explains here to BBC World Service programme Science in Action.
  68. We can definitely control the rate of mass loss,
  69. so it's definitely not a throw your hands up
  70. and just not do anything about, you know,
  71. give up on the ice sheet kind of situation.
  72. That's certainly not the message I want to send.
  73. But it does seem likely that we will continue to lose mass.
  74. But of course, a slow rate
  75. of mass loss is highly preferred
  76. to large annual losses every year.
  77. Michaela thinks that changes in human activity can still slow the rate
  78. or speed at which something happens.
  79. In this case, the speed of Greenland's ice sheet melting.
  80. She's convinced it's not too late
  81. for collective action to save the planet,
  82. so it's not yet time to throw your hands up –
  83. an idiom meaning to show frustration and despair when a situation becomes
  84. so bad that you give up or submit.
  85. It's a positive message, but one which calls for everyone
  86. to do what they can before it really is too late.
  87. Because the rate of ice melt is still increasing.
  88. Right, Neil? Yes, that's right.
  89. In fact, that was my quiz question, Georgina.
  90. Do you remember?
  91. Yes. You asked me how many gigatons
  92. of Greenland's ice sheet are now melting every year.
  93. I said b – 500 gigatons.
  94. And you were... Correct! In fact,
  95. some of these giant ice cubes
  96. are like small towns almost a kilometre tall.
  97. So, there's still work to be done.
  98. In this programme, we've been looking at the rate, or speed,
  99. of ice melt in Greenland's ice sheet –
  100. the thick layer of ice covering
  101. a large area of the Arctic.
  102. Previously, the melting ice was replaced by newly formed ice
  103. on glaciers – large masses of slow-moving ice.
  104. This kept the Arctic in balance,
  105. having different elements arranged in proportion.
  106. But the effects of global heating have brought
  107. us close to a point of no return,
  108. called a tipping point – the time at which a change
  109. or an effect cannot be stopped.
  110. The situation is serious, but there's still time to take action
  111. and not simply throw your hands up.
  112. Show frustration and despair when you want to give up.