Hey,this is a simplified version for acoustic guitars.I think this song can also be 
with chords on accoustic guitar. I'm using a D-Tuning, but it might also be okay 
in standard tuning.
Notice: In Verse it also might sound good to play G5 and F#5 instead of G an F#

Enjoy it.

Verse:

E5                                              G    F#    E5
 When our rivers run dry and our crops cease to grow
E5                                                  G    F# E5
 And when our summers grow longer and winters won't snow
          C                          A
 From the banks of the ocean and the ice in the hills
        E5                        B
 To the fight in the desert where progress stands still
 C                   A
 When we've lost our will


Chorus:

                  E5
 That's how we'll know
 G             A        E5
 This is not a test, oh no
         G        A
 This is cardiac arrest
      E5                   G          A
 Of a world too proud to admit our mistakes
       E5                G            A             E5
 We're crashing into the ground as we all fall from grace

Verse:

E5                                                G    F#    E5
 When the air that we breathe becomes air that we choke
E5                                                   G    F#  
 E5
 When the marsh fever spreads from the swamps to our homes
           C                          A
 When your home on the range has been torn down and paved and
     E5                B
 The buffalo roam to a slaughterhouse grave
 C                 A
 What more will it take

Chorus:

           E5
 For us to know
 G             A        E5
 This is not a test, oh no
         G       A
 This is cardiac arrest
      E5                   G          A
 Of a world too proud to admit our mistakes
 E5             G         A             E5
 Kissing the ground as we all fall from grace

Bridge:

E5                   C          A
 This is a chance to set things straight
E5                    C          A
 To bend or break the rules back into place
E5           C      A
 There is no middle ground, no compromise, we've drawn the line
      E5           C                 A
 With perfect aim, we stand back and throw
       E5                     C            A
 Glass windows break and it's all about to blow
 E5                  C              A
 Lights go out as we pass the torch again
    G                  D    B    C
 In hope that it stays lit

solo

     C                     A
 Neutrality means that you don't really care
           E5                    B
 Cause the struggle goes on even when you're not there
 C            A
 Blind and unaware

chorus:

                  E5
 That's how we'll know
 G             A        E5
 This is not a test, oh no
         G       A
 This is cardiac arrest
      E5                   G          A
 Of a world too proud to admit our mistakes
       E5                G            A                       
       E5
 We're crashing into the ground as we all, yeah we all, all fall from grace