This has been a concern since arctic ice and snow has been melting at higher rates due to higher temperatures, creating regions in the arctic that are notably darker (being water or ground which is darker color) and reflects less heat back into space.
ðɪs hˈæzbiːn ɐ kənsˈɜːn sˈɪns ˈɑːɹktɪk ˈaɪs ænd snˈoʊ hˈæzbiːn mˈɛltɪŋ æt hˈaɪɚ ɹˈeɪts dˈuː tə hˈaɪɚ tˈɛmpɹɪtʃɚz, kɹiːˈeɪɾɪŋ ɹˈiːdʒənz ɪnðɪ ˈɑːɹktɪk ðæt ɑːɹ nˈoʊɾəbli dˈɑːɹkɚ bˌiːɪŋ wˈɔːɾɚ ɔːɹ ɡɹˈaʊnd wˌɪtʃ ɪz dˈɑːɹkɚ kˈʌlɚ ænd ɹᵻflˈɛkts lˈɛs hˈiːt bˈæk ˌɪntʊ spˈeɪs.