Pendidikan di Indonesia saat ini tengah berfokus untuk menghasilkan individu yang mampu bersaing di abad 21.  Salah satu kemampuan abad 21 yakni kemampuan berpikir kritis. Kemampuan berpikir kritis diharapkan menjadi output dari proses pembelajaran di sekolah. Kurangnya intensitas terhadap pengembangan kemampuan ini menyebabkan harapan masih belum sesuai dengan fakta. Penelitian ini bertujuan untuk mendeskripsikan kualitas keterlaksanaan, peningkatan kemampuan berpikir kritis dan respon peserta didik terhadap  pembelajaran model inkuiri terbimbing pada materi pemanasan global. Penelitian menggunakan desain group pre-test and post-test dengan 3 kelas eksperimen. Instrumen yang digunakan adalah lembar keterlaksanaan, lembar tes dan lembar angket respon. Analisis data menggunakan analisis lembar keterlaksanaan dari pengamat, analisis uji t-berpasangan dan gain ternormalisasi serta analisis lembar angket respon. Hasil penelitian menunjukkan rata-rata penilaian keterlaksanaan pembelajaran menggunakan inkuiri terbimbing berkategori baik dan sangat baik, peningkatan kemampuan berpikir kritis di ketiga kelas berada pada kategori sedang dan tinggi sedangkan respon peserta didik mendapatkan rata-rata persentase berkategori sangat baik.

Kata Kunci : inkuiri terbimbing, kemampuan berpikir kritis, pemanasan global.

Education in Indonesia is currently being focused to produce individuals who are able to compete in the 21st century. One of the 21st century skills is the ability to think critically. Critical thinking skills are expected to be output from the learning process at school. The lack of intensity towards the development of these ability causes a gap between expectation and fact. This study aimed to describe the quality of learning implementation, improved critical thinking skills and the response of learners to the learning with guided inquiry model about global warming. This research using group pre-test and post-test design, with 3 experimental class. The instruments used were observation sheet for measure implementation of learning model, multiple choice test sheet for measure citical thinking ability, and questionnaire responses sheet to measure student respons. The improvement critical thinking ability analyzed by paired t-test and gain normalization. The results showed the average ratings of learning implementation with guided inquiry model were good and excellent category, improved critical thinking ability in third grade were middle and high category, while the response of learners get an average percentage in very good category. Overall implementation of guided inquiry can improve student critical thinking ability.

Keyword : guided inquiry, critical thinking ability, global warming.