ðiːz dˈeɪz, sˌʌm sˈaɪəntɪsts θˈɪŋk ðeɪ ɑːɹ kˈɔːzd baɪ spˈeɪs dˈʌst, wˌaɪl ˈʌðɚz bᵻlˈiːv ðæt mˈɑːdɚndˈeɪ pˌiːˌɛmsˈiːz ɑːɹ ˈɪndᵻkˌeɪɾɚz ʌv tʃˈeɪndʒɪŋ klˈaɪmət ʌv ˈɜːθ.
These days, some scientists think they are caused by space dust, while others believe that modern-day PMC's are indicators of changing climate of Earth.